Would you give us a little more information please. Mainly what you were doing w/ your iPhone when it started doing this? Did you drop it, get it wet, some type of Jailbreak or restore process? Thanks!!
i only restored it from itunes then it happened . but when i lock my iphone it turns to normal and then after a seconds . it will turn again into that issue . please help how to fix this
It's very likely that your screen is starting to fail. You should do a backup of your iPhone while you're still able to and take it to the Genius Bar at the closest Apple Store. They can do a full diagnostic and tell you the exact cause of the screen failure. If you have an iPhone 4 like the OP, you may want to consider upgrading as the iPhone 4 is up to 5 years old by now.