Abstract: The phenomenon that silicon oil drops stay on the vibrating liquid surface is found.Experiment of equal thickness interference indicates the existent of air film.Based on the analysis of the air film＇s transformation,a simplified model is proposed to explain how the air film inhibited the coalescing of drops and liquid surface.Drops underneath the liquid surface are observed and theoretical model is founded to calculate the thickness of air films,which is also compared with the experimental value.The paper also describes and explains the breath-mode vibrating phenomenon of multiple drops.

Key words: drop, liquid surface, vertical vibrating, noncoalescing phenomenon, air film