diff --git a/csharp/src/Microsoft.ML.OnnxRuntime/FixedBufferOnnxValue.cs b/csharp/src/Microsoft.ML.OnnxRuntime/FixedBufferOnnxValue.cs
index 92aab02a2f..206e87d035 100644
--- a/csharp/src/Microsoft.ML.OnnxRuntime/FixedBufferOnnxValue.cs
+++ b/csharp/src/Microsoft.ML.OnnxRuntime/FixedBufferOnnxValue.cs
@@ -31,16 +31,9 @@ namespace Microsoft.ML.OnnxRuntime
         /// <returns></returns>
         public static FixedBufferOnnxValue CreateFromTensor<T>(Tensor<T> value)
         {
-            if (value is Tensor<string>)
-            {
-                throw new ArgumentException("Only numeric tensors can be used to create FixedBufferOnnxValue.", nameof(value));
-            }
-
             NativeOnnxValueHelper.CreateNativeOnnxValue(value, out IntPtr onnxValue, out MemoryHandle pinnedMemoryHandle, out OnnxValueType onnxValueType, out TensorElementType elementType);
 
-            Debug.Assert(
-                onnxValueType == OnnxValueType.ONNX_TYPE_TENSOR && elementType != TensorElementType.String,
-                "the value should always be a numeric tensor");
+            Debug.Assert(onnxValueType == OnnxValueType.ONNX_TYPE_TENSOR, "the value should always be a tensor");
 
             return new FixedBufferOnnxValue(pinnedMemoryHandle, onnxValue, onnxValueType, elementType);
         }
diff --git a/csharp/src/Microsoft.ML.OnnxRuntime/InferenceSession.cs b/csharp/src/Microsoft.ML.OnnxRuntime/InferenceSession.cs
index e03a70e4d9..cd3145a4c3 100644
--- a/csharp/src/Microsoft.ML.OnnxRuntime/InferenceSession.cs
+++ b/csharp/src/Microsoft.ML.OnnxRuntime/InferenceSession.cs
@@ -366,6 +366,11 @@ namespace Microsoft.ML.OnnxRuntime
             int outputIndex = 0;
             foreach (var output in outputValues)
             {
+                if (output.ElementType == TensorElementType.String)
+                {
+                    throw new NotSupportedException("Using string type FixedBufferOnnxValue in outputs is not supported.");
+                }
+
                 outputValuesArray[outputIndex] = output.Value;
 
                 outputIndex++;
@@ -556,6 +561,11 @@ namespace Microsoft.ML.OnnxRuntime
                 int outputIndex = 0;
                 foreach (var output in outputValues)
                 {
+                    if (output.ElementType == TensorElementType.String)
+                    {
+                        throw new NotSupportedException("Using string type FixedBufferOnnxValue in outputs is not supported.");
+                    }
+
                     outputValuesArray[outputIndex] = output.Value;
 
                     outputIndex++;
@@ -695,7 +705,7 @@ namespace Microsoft.ML.OnnxRuntime
             IntPtr nameHandle = IntPtr.Zero;
             string str = null;
 
-            IntPtr status = NativeMethods.OrtSessionEndProfiling(_nativeHandle, 
+            IntPtr status = NativeMethods.OrtSessionEndProfiling(_nativeHandle,
                                                                   NativeMemoryAllocator.DefaultInstance.Handle,
                                                                   out nameHandle);
 
@@ -708,7 +718,7 @@ namespace Microsoft.ML.OnnxRuntime
             {
                 if (nameHandle != IntPtr.Zero)
                 {
-                  NativeMemoryAllocator.DefaultInstance.FreeMemory(nameHandle);
+                    NativeMemoryAllocator.DefaultInstance.FreeMemory(nameHandle);
                 }
             }
 
diff --git a/csharp/test/Microsoft.ML.OnnxRuntime.Tests/InferenceTest.cs b/csharp/test/Microsoft.ML.OnnxRuntime.Tests/InferenceTest.cs
index 1a5c2e94cb..38a70d923d 100644
--- a/csharp/test/Microsoft.ML.OnnxRuntime.Tests/InferenceTest.cs
+++ b/csharp/test/Microsoft.ML.OnnxRuntime.Tests/InferenceTest.cs
@@ -1056,12 +1056,41 @@ namespace Microsoft.ML.OnnxRuntime.Tests
         public void TestCreateFixedBufferOnnxValueFromStringTensor()
         {
             var tensor = new DenseTensor<string>(new string[] { "a", "b" }, new int[] { 1, 2 });
+            using (var value = FixedBufferOnnxValue.CreateFromTensor(tensor)) { }
+        }
 
-            Assert.Throws<ArgumentException>("value", () =>
+        [Fact]
+        public void TestReusingStringFixedBufferOnnxValue()
+        {
+            string modelPath = Path.Combine(Directory.GetCurrentDirectory(), "test_types_STRING.pb");
+            using (var session = new InferenceSession(modelPath))
             {
-                // cannot create from string tensor
-                FixedBufferOnnxValue.CreateFromTensor(tensor);
-            });
+                var tensorA = new DenseTensor<string>(new string[] { "a", "b", "c", "d", "e" }, new int[] { 1, 5 });
+                var tensorB = new DenseTensor<string>(new string[] { "v", "w", "x", "y", "z" }, new int[] { 1, 5 });
+                var tensorC = new DenseTensor<string>(new string[] { "i", "j", "k", "l", "m" }, new int[] { 1, 5 });
+                var tensorD = new DenseTensor<string>(new string[] { "i", "j", "k", "l", "m" }, new int[] { 1, 5 });
+                using (FixedBufferOnnxValue a = FixedBufferOnnxValue.CreateFromTensor(tensorA),
+                                            b = FixedBufferOnnxValue.CreateFromTensor(tensorB),
+                                            c = FixedBufferOnnxValue.CreateFromTensor(tensorC),
+                                            d = FixedBufferOnnxValue.CreateFromTensor(tensorD))
+                {
+                    // OK to use string type FixedBufferOnnxValue only in input
+                    session.Run(new[] { "input" }, new[] { a });
+
+                    // Cannot use string type FixedBufferOnnxValue in output
+                    Assert.Throws<NotSupportedException>(() =>
+                    {
+                        // NamedOnnxValue inputs
+                        session.Run(new[] { NamedOnnxValue.CreateFromTensor("input", tensorB) }, new[] { "output" }, new[] { b });
+                    });
+                    Assert.Throws<NotSupportedException>(() =>
+                    {
+                        // both FixedBufferOnnxValue for inputs and outputs
+                        session.Run(new[] { "input" }, new[] { c }, new[] { "output" }, new[] { d });
+                    });
+                }
+
+            }
         }
 
         [Fact]