my iphone 5s is new !! but it's not working it says that i should Stimulation it i tried by itunes and its still not working am really sad :"(

You need to plug it into a power source to charge it firstly and then put a sim card in it to activate it.

If is still does not work, then take it back to the Apple store that you bought it from or take it to the Genius bar at your local Apple store.