Abstract: In order to investigate the effects of pistacia chinensis bunge seed biodiesel on the performance of diesel engine, the economy and emissions test was carried out at the YTR3105 direct injection diesel engine fueled with pistacia chinensis bunge seed biodiesel-diesel blends. The results showed that the most economic fuel injection timing of the blends was almost the same at different operating conditions, namely, the most economic fuel injection timing of the blends was 11° crank angle before top dead center at the maximum torque condition and 12° crank angle before top dead center at rated condition. With the increase of fuel injection timing, both CO and smoke emissions of the engine decreased firstly and then increased, and THC emissions decreased, while NOX emissions increased greatly. CO, HC and smoke emissions decreased with the increase of the proportions of biodiesel in the blends. The NOX emissions of the engine fueled with B10 and B20 were lower than that of diesel, but higher when fueled with B30. It is concluded that there is no relationship between the most economic fuel injection timing and the fuel type, but the proportions of biodiesel in the blends greatly affect on the emissions of diesel engine.