In order to restrain the self-oscillations in Nd:YAG bounce laser,germanium wit h high absorption coefficient in near infrared region was sputtered on the non-light-passed surf aces of the gain medium. The laser outputs of free oscillator and passive Q-switched oscillator with ger manium and without germanium were compared respectively.Germanium could effectively decrease the pump thresh old and improve the pulse energy of outputs.The pulse energy of the free oscillator with Germa nium-sputtered Nd:YAG is improved by 51% compared with that of the free oscilla tor with non-germanium-sputtered Nd:YAG when the current of the pump is 68A.When the current of pump is 67A,the pulse ene rgy of the passive Q- switched oscillator with germanium-sputtered Nd:YAG is improved by 75% compare d with that of the free oscillator with non-germanium-sputtered Nd:YAG.