Abstract: Cross coupled map lattices system (CCML) has a special spatiotemporal behavior of “return diffusion”, which increases the complexity of the system, can be used to design sequence ciphers and data encryption, and has extremely high cryptographic application value. Tent map was chosen as the non-linear function of cross coupled map lattices and a detailed analysis of spatiotemporal behavior of “return diffusion” was conducted from invariant distribution feature, phase space structure, Lyapunov exponent and approximate entropy. The difference distribution characteristics, correlation characteristics and equilibrium degree of chaotic sequences generated by the system was analyzed. The relationship between system parameters and spatio-temporal behavior was determined, which provided a theoretical basis for the design of system cryptography.