An L9（33） of orthogonal experiment on batch anaerobic digestions was conducted in order to investigate the effects to biogas production characteristics by adding biochar in anaerobic digestion of chicken manure under the mesospheric condition (35±1)℃. The effects of the three factors including biochar concentration, inoculums concentration and biochar thickness on biogas production characteristics were determined. The optimal combination of these three factors was achieved. The results showed that the factors affect biogas production from highest to lowest were biochar concentration (very significant), biochar thickness (not significant), and inoculums concentration (not significant). The effect of thickness of biochar to methane contents achieved a very significant level.