Abstract: Because the rights have a very important meaning in contemporary society,they need very to be justified.The justification means to put the rights on a firm base.There are three justifications of rights in political philosophy,which they are theory of the natural rights,the will theory,and the interest theory.The theory of natural rights has a very long history,but it is most disadvantaged of the three theories.The most contemporary political philosophies agree with the will theory,or the interest theory,but both of them have some difficulties.Generally,the interest theory can explain rights rationally,but it can‘t explain obligations rationally; The will theory can‘t rationally explain both of rights and obligations.So,we need to construct a better theory for rights,that is “consequentialist contractualism”.