In this paper a proposedmethod to encrypt images based Liu Hyper Chaotic System(LHCS)is presented. In the proposed algorithm is used to generate a key for diffusion process, to confuse relationships between the input image and encrypted image. Besides of the four initial states (initial keys) in LHCS, six control parameters were used to increase the key space. Simulation results show that the proposed method has large key space (key space is 1070), and it is responsive to a trivial change of the key.Therefore it withstands different types of attacks such as brute force, differential, and chosen-cipher text attacks.