Abstract: The atomizing process in atomizing channel has been investigated by means of pulse laser. The results show that most of atomizing spray comes from the unstable atomization of fuel film on the front edge of the channel. The recirculation znoe of the channel impels the fuel film to turn over from the inside to outside of the channel. The width of the fuel film and recirculation zone of the channel have also been measured. An empirical expression for fuel fiim width has been deduced.