Different density levels of earthworm were tried to determine the optimum initial population to be released for efficient biodegradation of organic waste. Paddy straw and sugarcane trash were selected as feeds for the purpose. Though higher biomass and vermicompost was produced at high density level (30 worms 0.1.m² area), the rate of increase in biomass accumulation and productivity of vermicompost was higher at lower density levels. The release of 15 worms per 0.1m² area proved to be optimum for biodegradation of organic wastes.