The key is the important part at any security system because it determines whether the system is strength or weakness. This paper aimed to proposed new way to generate keystream based on a combination between 3D Henoun map and 3D Cat map. The principle of the method consists in generating random numbers by using 3D Henon map and these numbers will transform to binary sequence. These sequence positions is permuted and Xoredusing 3D Cat map. The new key stream generator has successfully passed theNIST statistical test suite. The security analysisshows that it has large key space and its very sensitive initial conditions.