Abstract: In this paper the theoretical foundation of commutative hyper-operator method has been discussed.The results show that the operator set defined by commutative hyperoper-ator is a Lie algebra, the definition of commutative hyper-operator is just that of the inner derivation in Lie algebra.From this, some algebric relations between commutative hyper-operators were obtained. It is verified that hyper-opera tor set derived from operators in g is also a Lie algebra.It is shown that a Lie group derived from covering group and defined by inner product corresponds to g.and the hyper-operators of angular momentum are generated by direct product between inner angular momentum of a vector field and unit operator.The conclusion is that the theoretical foundation of commutative hyper-operator method is Lie algebra.