The statistical properties of mobile cascade channel in amplify-and-forward (AF) two-way relay networks (TWRN) is focused on. Based on the statistical properties of double Gaussian, the mobile cascade channel is divided into transmission and interference processes. In addition, the probability distribution functions (PDF), temporal auto-correlation functions (ACF) and Doppler spectrums of the two processes are derived, respectively. Furthermore, by approximating the PDFs of the cascade channel by the concise Gamma distributions, closed-form and approximated expressions of two critical temporal merits, level-crossing rate (LCR) and average duration of fades (ADF), are provided. Numerical simulation demonstrates the validity of the proposed expressions. 