|This study is precedent performance characteristic study of the biodiesel boiler. Spray image analysis of pressure nozzle was carried out on various injection pressure conditions and horizontal spray condition. Spray image was obtained by the image acquisition device (halogen light, high speed camera) and the fuel supply device (biodiesel chamber, regulator, pressure gage). Fuels used in the experiment are Lard, Soybean and Kerosene. Through the experiment, spray angle and spray velocity were measured.