Abstract: In this study, the effect of fuel injection pressure on spray characterization of mahua biodiesel blend (B20) was visually analysed using CRDI fuel injection system. To analyse the spray characteristics, biodiesel blend fuel (B20) has injected at different injection pressures like 20, 30, 40and 50 MPa pressures. The fuel injection pressures and fuel injection durations were varied using electronic control module fitted with CRDI system. The spray structure of mahua biodiesel blend (B20) were recorded using a high-speed camera. For testing purpose one port of CRDI unit was connected with the solenoid fuel injector and other ports were closed. From the results obtained, it is clear that the spray tip penetration and spray cone angle were increased when the fuel injection pressure was increased from 20 to 50 MPa.