Abstract: In order to evaluate the performance of diesel engine fueled by Jatropha based biodiesel, this paper carried out power performance, fuel economy and emission characteristics of a common rail diesel engine fueled with jatropha biodiesel blends. The studying indicators include the engine power, torque, fuel consumption, HC, CO, NOX, smoke, and CO2 emissions. According to the bench test results, the engine power, torque, HC, CO, somke and CO2 emissions decreased with the biodiesel blend ratio increasing, whereas, the fuel consumption and NOX emission of jatropha biodiesel blends fueled engine increased with the biodiesel blend ratio increasing.