Promising candidates in this respect are organometal perovskites ABX3, which have been intensely investigated during the last years. In this work, we have calculated the geometry optimization, band structure, optical properties and carrier mobility for tetragonal phase of non-toxic perovskite halide CH3NH3SnCl3 and CH3NH3SnI3 by applying density functional theory (DFT) with the generalized gradient approximation (GGA) correlation of Perdew-Berke-Erzndof (PBE). The results have showed that CH3NH3SnCl3and CH3NH3SnI3 have good optical absorption coefficient, which can be a good application for solar light harvester.