The laser-induced cavitation bubble collapse sound waves in viscous liquid are measured by the PZT hydrophone.In combination with analyzing the maximum bubble radius and oscillating duration influenced by the gas content and kinematic viscosity in viscous liquid,the sound waves spectrum properties influenced by the gas content and kinematic viscosity are investigated by experiment.The results indicate that the gas content decreases with the increase of kinematic viscosity under the same laser energy.The longer the oscillating duration,the smaller the maximal bubble radius,and the frequency peak trends higher direction.