Abstract: The essence of social contract theory is the validity of right,which claims that all rights,including supreme power,are valid and that they all come from general agreement or social contract.Starting from this,social contract theory finds that there is only one way to establish supreme power or a state,that is,to make a social contract,either expressed or implied.It is a general agreement on the exchange of right and obligation relating to supreme right,thus supreme power or a state is originated from the expressed or implied social contract.

Key words: contract, validity, supreme power, natural state