Due to the random-like property and high sensitivity for initial values and parameters, chaotic systems are usually proposed as a solution to image encryption. In this study, the authors introduce a new chaotic system called LS chaotic system using the Logistic map and Sine map. It shows excellent chaotic behaviors. Applying the new chaotic system, a novel image encryption algorithm is also introduced based on the substitution and permutation network structure. The experimental results show that the proposed algorithm's excellent performance in image encryption. It can also be applied to provide security for other multimedia. © 2012 IEEE.