In high speed turbopumps, various types of cavitations such as a blade surface cavitation, a tip leakage vortex cavitation, and a backflow vortex cavitation occur. When the cavitations response to encourage fluctuations of a pressure and a flow rate, the oscillation of the flow rate called a cavitation surge can occur. Therefore, clarifications of the dynamic characteristics of cavitations are desired to obtain higher reliability of turbopumps. Focusing on the blade surface cavitation as one of fundamental cavitations, we investigated unsteady characteristics of the blade surface cavitation in a flat plate hydrofoil, the Clark-Y 11.7% hydrofoil, and the NACA0015 hydrofoil in experiments. Several interesting characteristics of the blade surface cavitation were clarified.