In order to elucidate the mechanism of cavitation erosion, the dynamics of a single laser-generated cavitation bubble in water is investigated in detail. Employing a new force sensor, the characteristics of bubble dynamics,in particular the formarion of a high-speed liquid jet and the emission of acoustic transient are experimentally measured. The experimental results indicate that acoustic transient emission and liquid jet are both predominant features on the cavitation erosion,and the diemnsionless 7 is the decisive factor.