diff --git a/sandbox/ConsoleApp1/Program.cs b/sandbox/ConsoleApp1/Program.cs
index 784196b6..d85d85f5 100644
--- a/sandbox/ConsoleApp1/Program.cs
+++ b/sandbox/ConsoleApp1/Program.cs
@@ -1,48 +1,50 @@
 using R3;
 using System.ComponentModel.DataAnnotations;
 using System.Runtime.CompilerServices;
+using System.Text.Json;
+using System.Text.Json.Serialization;
+using System.Text.Json.Serialization.Metadata;
 
 
 Console.WriteLine("hello");
-// System.Linq.AsyncEnumerable.Range(1,10)
 
 
-//Dump.Factory();
 
-//System.Reactive.Linq.Observable.Range(1,10).SelectMany(
-
-//var onClick = new Subject<Unit>();
-//var httpClient = new HttpClient();
+//JsonSerializerOptions.Default.TypeInfoResolver
+// JsonSerializerOptions.Default.Converters.Add(new IgnoreCaseStringReactivePropertyJsonConverter());
 
+var options = new JsonSerializerOptions
+{
+    Converters = { new IgnoreCaseStringReactivePropertyJsonConverter() },
+};
 
-//onClick.SelectAwait(async x =>
-//{
+var v = new IgnoreCaseStringReactiveProperty("aaa");
 
+// var v = new ReactiveProperty<int>(1000);
 
-//});
 
+var json = JsonSerializer.Serialize(v, options);
+Console.WriteLine(json);
+var v2 = JsonSerializer.Deserialize<IgnoreCaseStringReactiveProperty>(json, options);
+Console.WriteLine(v2!.Value);
 
 
-Observable.Create<int>(observer =>
-{
-    observer.OnNext(1);
 
-    return Disposable.Empty;
-});
 
-Observable.Create<int>(async (observer, ct) =>
+//[JsonConverter(typeof(IgnoreCaseStringReactivePropertyJsonConverter))]
+public class IgnoreCaseStringReactiveProperty : ReactiveProperty<string>
 {
-    observer.OnNext(1);
-    await Task.Delay(1000, ct);
-});
+    public IgnoreCaseStringReactiveProperty(string value)
+        : base(value, StringComparer.OrdinalIgnoreCase)
+    {
 
-Observable.CreateFrom(Gen);
+    }
+}
 
-static async IAsyncEnumerable<int> Gen([EnumeratorCancellation] CancellationToken ct)
+internal class IgnoreCaseStringReactivePropertyJsonConverter : ReactivePropertyJsonConverter<string>
 {
-    yield return 1;
-    await Task.Delay(1000, ct);
-    yield return 2;
-    await Task.Delay(1000, ct);
-    yield return 3;
+    protected override ReactiveProperty<string> CreateReactiveProperty(string value)
+    {
+        return new IgnoreCaseStringReactiveProperty(value);
+    }
 }
diff --git a/src/R3/BindableReactiveProperty.cs b/src/R3/BindableReactiveProperty.cs
index e877f56a..1bee9737 100644
--- a/src/R3/BindableReactiveProperty.cs
+++ b/src/R3/BindableReactiveProperty.cs
@@ -15,6 +15,10 @@ public interface IBindableReactiveProperty
 }
 
 // all operators need to call from UI Thread(not thread-safe)
+
+#if NET6_0_OR_GREATER
+[System.Text.Json.Serialization.JsonConverter(typeof(BindableReactivePropertyJsonConverterFactory))]
+#endif
 public class BindableReactiveProperty<T> : ReactiveProperty<T>, INotifyPropertyChanged, INotifyDataErrorInfo, IBindableReactiveProperty
 {
     // ctor
diff --git a/src/R3/ReactiveProperty.cs b/src/R3/ReactiveProperty.cs
index a6859552..36ae56ac 100644
--- a/src/R3/ReactiveProperty.cs
+++ b/src/R3/ReactiveProperty.cs
@@ -1,4 +1,10 @@
-namespace R3;
+#if NET6_0_OR_GREATER
+using System.Reflection;
+using System.Text.Json;
+using System.Text.Json.Serialization;
+#endif
+
+namespace R3;
 
 public abstract class ReadOnlyReactiveProperty<T> : Observable<T>, IDisposable
 {
@@ -12,6 +18,10 @@ protected virtual void OnReceiveError(Exception exception) { }
 // almostly same code as Subject<T>.
 
 // allow inherit
+
+#if NET6_0_OR_GREATER
+[JsonConverter(typeof(ReactivePropertyJsonConverterFactory))]
+#endif
 public class ReactiveProperty<T> : ReadOnlyReactiveProperty<T>, ISubject<T>
 {
     T value;
@@ -182,3 +192,101 @@ public void Dispose()
         }
     }
 }
+
+#if NET6_0_OR_GREATER
+
+public class ReactivePropertyJsonConverterFactory : JsonConverterFactory
+{
+    public override bool CanConvert(Type typeToConvert)
+    {
+        return GetReactivePropertyType(typeToConvert) != null;
+    }
+
+    public override JsonConverter? CreateConverter(Type typeToConvert, JsonSerializerOptions options)
+    {
+        var t = GetReactivePropertyType(typeToConvert);
+        if (t != null)
+        {
+            var rt = GenericConverterType.MakeGenericType(t.GetGenericArguments()[0]);
+            return (JsonConverter?)Activator.CreateInstance(rt, false);
+        }
+        else
+        {
+            return null;
+        }
+    }
+
+    Type? GetReactivePropertyType(Type? type)
+    {
+        while (type != null)
+        {
+            if (type.IsGenericType && type.GetGenericTypeDefinition() == typeof(ReactiveProperty<>))
+            {
+                return type;
+            }
+
+            type = type.BaseType;
+        }
+        return null;
+    }
+
+    // allow customize
+    protected virtual Type GenericConverterType => typeof(ReactivePropertyJsonConverter<>);
+}
+
+public class ReactivePropertyJsonConverter<T> : JsonConverter<ReactiveProperty<T>>
+{
+    public override void Write(Utf8JsonWriter writer, ReactiveProperty<T> value, JsonSerializerOptions options)
+    {
+        JsonSerializer.Serialize(writer, value.Value, options);
+    }
+
+    public override ReactiveProperty<T>? Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
+    {
+        var v = JsonSerializer.Deserialize<T>(ref reader, options);
+        return CreateReactiveProperty(v!);
+    }
+
+    // allow customize
+    protected virtual ReactiveProperty<T> CreateReactiveProperty(T value)
+    {
+        return new ReactiveProperty<T>(value);
+    }
+
+    public override bool CanConvert(Type typeToConvert)
+    {
+        return GetReactivePropertyType(typeToConvert) != null;
+    }
+
+    Type? GetReactivePropertyType(Type? type)
+    {
+        while (type != null)
+        {
+            if (type.IsGenericType && type.GetGenericTypeDefinition() == typeof(ReactiveProperty<>))
+            {
+                return type;
+            }
+
+            type = type.BaseType;
+        }
+        return null;
+    }
+}
+
+// for BindableReactiveProperty
+
+internal class BindableReactivePropertyJsonConverterFactory : ReactivePropertyJsonConverterFactory
+{
+    protected override Type GenericConverterType => typeof(BindableReactivePropertyJsonConverter<>);
+}
+
+internal class BindableReactivePropertyJsonConverter<T> : ReactivePropertyJsonConverter<T>
+{
+    protected override ReactiveProperty<T> CreateReactiveProperty(T value)
+    {
+        return new BindableReactiveProperty<T>(value);
+    }
+}
+
+
+#endif