In this paper, a new image encryption technique is proposed based on the combination of the pixel shuffling and S-box of AES encryption algorithm. Firstly, the Arnold cat map is used to shuffle the positions of the image pixels in the spatial-domain. Then the shuffled image is encrypted by nonlinear byte-substitution using S-box. In order to evaluate the performance, the proposed algorithm was executed through a series of tests. Experimental results demonstrate that the presented algorithm shows an appropriate resistance against statistical attacks but it is weak against differential analysis.