In this article, we calculated and modeled the gain of In0.53Ga0.47As/InP avalanche photodiode (APD) based on a device mechanism and carrier rate equations using transfer matrix method (TMM). In fact, a distributed model was presented for calculating impact ionization (I2) and relating different sections of the multiplication region. In this proposed model, recessive equations were used, and device gain is considered proportional to the number of output photo-electrons and photo-holes. By comparison of simulated results with experimental data available in literature, it has been demonstrated the capability of the developed model as a powerful tool for simulating APDs’ behavior and interpreting their experimentally measured characteristics.