Abstract: Formation,variation and atomization of a liquid layer in a two-dimensional airblast atomizer have been investigated theoretically and experimentally.A physical model of atomization was proposed in the analysis,the unstable N-S equations of the two-dimensional liquid layer were solved,and the expressions for liquid layer thickness h and mean drop diameter Dm have been derived as follows: at lower air velocity and smaller liquid viscosity conditionat higher air velocity conditionand Comprehensive experiments have been done.A pulse laser photomicrography was applied to observing the details of the atomization process of a liquid layer and the pictures taken were quite distinct.A light-scattering technique with laser as light source was used to measure the mean drop diameter D32 The results testified that D32 was proportional to ug-1.7 at lower air velocity and to ug-1 at higher air velocity.A method with a probe measuring electrical resistance of a water layer was employed to determine the thickness of the water layer.The data of experiments were consistent with the theoretical analysis,and the semiempirical equations were yielded as follows:water.Kerosene: