Spray characteristics of biodiesel were investigated by using phase Doppler particle analyzer (PDPA) at different injection pressures, pump speeds and orifice diameters. Meanwhile, several highspeed digital pictures of spray for biodiesel and 0 type diesel were taken respectively. The experimental results show that Sauter mean diameter (SMD) of biodiesel spraying droplets decreases as the injection pressure increases and the orifice diameter diminishes, which is similar to petrochemical diesel. However, SMD of biodiesel spraying drop lets changes slowly at different pump speeds.  