diff --git a/src/Neo.SmartContract.Framework/ByteString.Extension.cs b/src/Neo.SmartContract.Framework/ByteString.Extension.cs
new file mode 100644
index 000000000..eeae195d4
--- /dev/null
+++ b/src/Neo.SmartContract.Framework/ByteString.Extension.cs
@@ -0,0 +1,109 @@
+using Neo.SmartContract.Framework.Native;
+namespace Neo.SmartContract.Framework;
+
+public static class ByteStringExtension
+{
+    /// <summary>
+    ///  Denotes whether provided character is a number.
+    /// </summary>
+    /// <param name="byteString">Input to check</param>
+    /// <returns>True if is number</returns>
+    public static bool IsNumber(this ByteString byteString)
+    {
+        foreach (var value in byteString)
+        {
+            if (value is < 48 or > 57)
+                return false;
+        }
+        return true;
+    }
+
+    /// <summary>
+    ///  Denotes whether provided character is a lowercase letter.
+    /// </summary>
+    /// <param name="byteString">Input to check</param>
+    /// <returns>True if is Alpha character</returns>
+    public static bool IsLowerAlphabet(this ByteString byteString)
+    {
+        foreach (var value in byteString)
+        {
+            if (value is < 97 or > 122)
+                return false;
+        }
+        return true;
+    }
+
+    /// <summary>
+    ///  Denotes whether provided character is a lowercase letter.
+    /// </summary>
+    /// <param name="byteString">Input to check</param>
+    /// <returns>True if is Alpha character</returns>
+    public static bool IsUpperAlphabet(this ByteString byteString)
+    {
+        foreach (var value in byteString)
+        {
+            if (value is < 65 or > 90)
+                return false;
+        }
+        return true;
+    }
+
+    /// <summary>
+    ///  Denotes whether provided character is a lowercase letter.
+    /// </summary>
+    /// <param name="byteString">Input to check</param>
+    /// <returns>True if is Alpha character</returns>
+    public static bool IsAlphabet(this ByteString byteString)
+    {
+        foreach (var value in byteString)
+        {
+            if (!((value >= 65 && value <= 90) || (value >= 97 && value <= 122)))
+                return false;
+        }
+        return true;
+    }
+
+    /// <summary>
+    /// Returns the index of the first occurrence of a given value in an array.
+    /// </summary>
+    /// <param name="byteString">Array where to search.</param>
+    /// <param name="byteToFind">Array to search.</param>
+    /// <returns>Index where it is located or -1</returns>
+    public static int IndexOf(this ByteString byteString, ByteString byteToFind)
+    {
+        return StdLib.MemorySearch(byteString, byteToFind);
+    }
+
+    /// <summary>
+    /// Determines whether the beginning of this string instance matches the specified string when compared using the specified culture.
+    /// </summary>
+    /// <param name="byteString">Array where to search.</param>
+    /// <param name="byteToFind">Array to search.</param>
+    /// <returns>True if start with</returns>
+    public static bool StartWith(this ByteString byteString, ByteString byteToFind)
+    {
+        return StdLib.MemorySearch(byteString, byteToFind) == 0;
+    }
+
+    /// <summary>
+    /// Determines whether the end of this string instance matches a specified string.
+    /// </summary>
+    /// <param name="byteString">Array where to search.</param>
+    /// <param name="byteToFind">Array to search.</param>
+    /// <returns>True if ends with</returns>
+    public static bool EndsWith(this ByteString byteString, ByteString byteToFind)
+    {
+        return StdLib.MemorySearch(byteString, byteToFind) + byteToFind.Length == byteString.Length;
+    }
+
+    /// <summary>
+    /// Checks if the <see cref="ByteString"/> contains the given <see cref="ByteString"/>.
+    /// </summary>
+    /// <param name="byteString"><see cref="ByteString"/> to search.</param>
+    /// <param name="byteToFind"><see cref="ByteString"/> to be searched.</param>
+    /// <returns></returns>
+    public static bool Contains(this ByteString byteString, ByteString byteToFind)
+    {
+        return StdLib.MemorySearch(byteString, byteToFind) != -1;
+    }
+}
diff --git a/tests/Neo.SmartContract.Framework.TestContracts/Contract_Regex.cs b/tests/Neo.SmartContract.Framework.TestContracts/Contract_Regex.cs
new file mode 100644
index 000000000..718ef879b
--- /dev/null
+++ b/tests/Neo.SmartContract.Framework.TestContracts/Contract_Regex.cs
@@ -0,0 +1,45 @@
+namespace Neo.SmartContract.Framework.UnitTests.TestClasses
+{
+    public class Contract_Regex : SmartContract
+    {
+        public static bool TestStartWith()
+        {
+            return ((ByteString)"Hello World").StartWith("Hello");
+        }
+
+        public static int TestIndexOf()
+        {
+            return ((ByteString)"Hello World").IndexOf("o");
+        }
+
+        public static bool TestEndWith()
+        {
+            return ((ByteString)"Hello World").EndsWith("World");
+        }
+
+        public static bool TestContains()
+        {
+            return ((ByteString)"Hello World").Contains("ll");
+        }
+
+        public static bool TestNumberOnly()
+        {
+            return ((ByteString)"0123456789").IsNumber();
+        }
+
+        public static bool TestAlphabetOnly()
+        {
+            return ((ByteString)"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz").IsAlphabet();
+        }
+
+        public static bool TestLowerAlphabetOnly()
+        {
+            return ((ByteString)"abcdefghijklmnopqrstuvwxyz").IsAlphabet();
+        }
+
+        public static bool TestUpperAlphabetOnly()
+        {
+            return ((ByteString)"ABCDEFGHIJKLMNOPQRSTUVWXYZ").IsAlphabet();
+        }
+    }
+}
diff --git a/tests/Neo.SmartContract.Framework.UnitTests/RegexTest.cs b/tests/Neo.SmartContract.Framework.UnitTests/RegexTest.cs
new file mode 100644
index 000000000..4ff505b97
--- /dev/null
+++ b/tests/Neo.SmartContract.Framework.UnitTests/RegexTest.cs
@@ -0,0 +1,82 @@
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+using Neo.VM.Types;
+using Neo.SmartContract.TestEngine;
+
+namespace Neo.SmartContract.Framework.UnitTests
+{
+    [TestClass]
+    public class RegexTest
+    {
+        private TestEngine.TestEngine _engine;
+
+        [TestInitialize]
+        public void Init()
+        {
+            _engine = new TestEngine.TestEngine(snapshot: new TestDataCache());
+            _engine.AddEntryScript(Utils.Extensions.TestContractRoot + "Contract_Regex.cs");
+        }
+
+        [TestMethod]
+        public void TestStartWith()
+        {
+            var result = _engine.ExecuteTestCaseStandard("testStartWith");
+            Assert.AreEqual(1, result.Count);
+            var item = result.Pop<Boolean>();
+            Assert.IsTrue(item.GetBoolean());
+        }
+
+        [TestMethod]
+        public void TestIndexOf()
+        {
+            _engine.Reset();
+            var result = _engine.ExecuteTestCaseStandard("testIndexOf");
+            Assert.AreEqual(1, result.Count);
+            var item = result.Pop<Integer>();
+            Assert.AreEqual(4, item.GetInteger());
+        }
+
+        [TestMethod]
+        public void TestEndWith()
+        {
+            var result = _engine.ExecuteTestCaseStandard("testEndWith");
+            Assert.AreEqual(1, result.Count);
+            var item = result.Pop<Boolean>();
+            Assert.IsTrue(item.GetBoolean());
+        }
+        [TestMethod]
+        public void TestContains()
+        {
+            var result = _engine.ExecuteTestCaseStandard("testContains");
+            Assert.AreEqual(1, result.Count);
+            var item = result.Pop<Boolean>();
+            Assert.IsTrue(item.GetBoolean());
+        }
+
+        [TestMethod]
+        public void TestNumberOnly()
+        {
+            var result = _engine.ExecuteTestCaseStandard("testNumberOnly");
+            Assert.AreEqual(1, result.Count);
+            var item = result.Pop<Boolean>();
+            Assert.IsTrue(item.GetBoolean());
+        }
+
+        [TestMethod]
+        public void TestAlphabetOnly()
+        {
+            var result = _engine.ExecuteTestCaseStandard("testAlphabetOnly");
+            Assert.AreEqual(1, result.Count);
+            Assert.IsTrue(result.Pop<Boolean>().GetBoolean());
+
+            _engine.Reset();
+            result = _engine.ExecuteTestCaseStandard("testLowerAlphabetOnly");
+            Assert.AreEqual(1, result.Count);
+            Assert.IsTrue(result.Pop<Boolean>().GetBoolean());
+
+            _engine.Reset();
+            result = _engine.ExecuteTestCaseStandard("testUpperAlphabetOnly");
+            Assert.AreEqual(1, result.Count);
+            Assert.IsTrue(result.Pop<Boolean>().GetBoolean());
+        }
+    }
+}
diff --git a/tests/Neo.SmartContract.Framework.UnitTests/Services/ContractTest.cs b/tests/Neo.SmartContract.Framework.UnitTests/Services/ContractTest.cs
index b05518240..aa364aec8 100644
--- a/tests/Neo.SmartContract.Framework.UnitTests/Services/ContractTest.cs
+++ b/tests/Neo.SmartContract.Framework.UnitTests/Services/ContractTest.cs
@@ -5,7 +5,6 @@
 using Neo.VM;
 using Neo.VM.Types;
 using System;
-using Neo.Persistence;
 using Neo.SmartContract.TestEngine;
 using Array = Neo.VM.Types.Array;
 
diff --git a/tests/Neo.SmartContract.Template.UnitTests/templates/neocontractoracle/OracleRequestTests.cs b/tests/Neo.SmartContract.Template.UnitTests/templates/neocontractoracle/OracleRequestTests.cs
index 38b3fd537..c9a83b933 100644
--- a/tests/Neo.SmartContract.Template.UnitTests/templates/neocontractoracle/OracleRequestTests.cs
+++ b/tests/Neo.SmartContract.Template.UnitTests/templates/neocontractoracle/OracleRequestTests.cs
@@ -9,7 +9,7 @@
 namespace Neo.SmartContract.Template.UnitTests.templates.neocontractowner
 {
     /// <summary>
-    /// You need to build the solution to resolve Ownable class.
+    /// You need to build the solution to resolve OracleRequest class.
     /// </summary>
     [TestClass]
     public class OracleRequestTests : TestBase<OracleRequest>