Isothermal and nonisothermal methods were used to investigate the kinetics of oil generation during decomposition of 91.7 l/tonne (22-gal/ton) Colorado oil shale. The average of the results from these two methods gives an activation energy of 52.0 kcal/mole and a frequency factor of 3 x 10/sup 13/s/sup -1/. The process is found to be first order to within experimental error. These results compare favorably with data reported in the literature. The reliability and ease of carrying out nonisothermal kinetic experiments to study solid decomposition reactions is demonstrated. Moreover, nonisothermal experiments more accurately simulate actual in situ processing conditions.