测试了一下Unity5.3自己带的json，不错

using UnityEngine;
using System.Collections;

public class TestJson : MonoBehaviour {

// Use this for initialization
public MyClass myObject = new MyClass();
public MyClass myObjectRead = new MyClass();

[System.Serializable]
public class MyClass
{
public int level;
public float timeElapsed;
public string playerName;
}
void Start () {

myObject.level = 1;
myObject.timeElapsed = 47.5f;
myObject.playerName = "Dr Charles Francis";
string json = JsonUtility.ToJson(myObject);
print ("" + json);
myObjectRead = JsonUtility.FromJson<MyClass> (json);
}

// Update is called once per frame
void Update () {

}
}

感觉挺好用的，支持unity