Abstract: Aim at the industrial atomization process, the influence of surface tension, viscous drag and other physical properties of liquid on the atomizing effect were discussed. The two-flow outside-mixing atomizer was used to test the N46 lube and #150 gear oil, for which the viscosity and surface tension are different, and the size of atomized droplets and their distributions were measured by the laser particle size analyzer CLY-2003. The results showed that both viscosity and surface tension are the restricting factors to the increase in surface wave amplitude. Under the same atomizing pressure, the size of the droplets whose viscosity and surface tension are comparatively higher is relatively bigger, i.e., the atomizing effect is relatively poor.