the final result indicates the maximum methane (24%) was obsered in the ratio of 50%WH + 50% CD followed by 25%WH + 75%CD (21.42%) on 30th day and 75% WH+25% CD combination showed very low level of methane (8.25%) Figure.1. It has been already reported that the mixture of cow dung and water hyacinth slurry has proven to produce more biogas than when used alone [15]