Abstract: An experimental study of the spray characteristics of side unlike impinging platelet injector was conducted using a Particle Dynamics Analyzer (PDA).The droplet velocities,diameter and flux density of the spray were measured at three axial locations.The atomization process and special spray feature have been analyzed.The results show that the atomization process is different from that of common impinging injector.The mixing ratio γ_mand geometric parameters have important effect on the atomization and spray distribution.For a certain γ_mand passage area ratio γ_a,there is an optimum nozzle geometry to attain good atomization and spray pattern.On the other hand,both higher γ_aand γ_mcan improve atomization performance within an appropriate nozzle width.The atomization performance and spray pattern can be controlled by selecting appropriate and geometric parameters.