Under different inlet pressures and ventilated velocities, the moving process of ventilated bubble in micro scale venturi was recorded by high speed camera system. The effects of inlet pressure and ventilated velocity on bubble dynamics were analyzed in detail. The results show that the bubble breakup depends on the flow pattern. Bubble breaks up in turbulent flow but not in laminar flow. The intensity of bubble breakup becomes more severe with the increase of turbulent intensity. The main mechanism of bubble breakup in venturi is turbulence fluctuation and shearing-off process, the former happens in the condition of high inlet pressure and the latter exits when the inlet pressure is relatively low. (C) 2015 Elsevier B.V. All rights reserved.