Abstract: This paper analyzes the origin and purpose of morality.It contains the following arguments:morality,like law,is a kind of evil,a necessary evil;virtue,like morality,is also a kind of necessary evil;the origin and purpose of morality is not self-disciplined,it is the special and direct origin,purpose,and criterion of morality that brings benefit to non-human existence,while human benefit is brought by the ultimate origin,purpose,and criterion of it.On the one hand,when human benefit is in coincidence with that of non-human existence,the special,direct purpose and criterion of morality should be followed,on the hand,when conflicts occur between them,we should follow the ultimate purpose and criterion of it to protect human benefit.

Key words: necessary evil, pure good, the direct origin and purpose of morality, the ultimate origin and purpose of morality