Abstract: The relahonship between hobbing force and vibration, and the effect of paramertes and cutting methods on the hobbing force have been studied.The results show that the alternative action of hobbing force resuls in the forced vibration in bobbing process, the characteristic of hobbingg is the cause of the self- exited vibration condition.By selected cutting tools, cutting parameters and cutting methods reasonably can prevent the self-exited vibrahon and avod resonance and forced vibration.