DontDestroyOnloadを使用した例

LoadScene.cs

using UnityEngine;
using System.Collections;

public class LoadScene : MonoBehaviour 
{
	public int score = 0;

	void Awake()
	{
		score = 30;
		DontDestroyOnLoad (gameObject);
	}

	// click callback
	public void OnClick()
	{
		Application.LoadLevel (1);
	}
}

ReadData.cs

using UnityEngine;
using System.Collections;

public class ReadData : MonoBehaviour 
{
	void Start () 
	{
		LoadScene loadScene = FindObjectOfType<LoadScene> ();
		Debug.Log (loadScene.score);
	}
}