A simple method, supplying water with Jatropha oil, was proposed to enhance the conversion of selectivity of lower olefins over zeolite catalysts, H-ZSM-5 and SAPO-11. The yield of lower olefins was as high as 54C mol%, and the selectivity for lower olefins reached 58C mol%. The optimum condition on catalytic conversion of jatropha oil was 600 degrees C of reaction temperature, 3.0s of contact time and 0.7 of water fraction with SAPO-11. The presence of water effectively suppressed the progress of Diels-Alder and hydrogen transfer reaction probably due to the reduced number of acid sites.