The kinetics of thermo-chemical hydrolysis of waste activated sludge from wastewater treatment plant and yeast has been studied under different environmental conditions. In order to determine the effect of thermo-chemical hydrolysis, the experiments have been performed at different temperatures, time intervals and pHs. It has been observed that increasing temperature and hydrolysis time increased the rate and extent of hydrolysis. Under these conditions, the extent of solubility increased for values between pH (2-3) and between pH (10-11). The increased temperature has also increased the efficiency of hydrolysis, and the solubility of COD in biomass has also increased up to 18-85% of mass for activated sludge and yeast under different experimental conditions. The kinetics of hydrolysis has been found to fit first order kinetics.