Based on the theory of role-based access control, a method of finely granular access control in object orient programming is proposed in this paper. Introducing the idea about finely granular access control through Inherit attributes of object, decomposes the access privilege from menu to atom control. The privilege is assigned to role, then access control can be manage easily by defining the user of the role to simplify management of permissions. Finally, the specific implementation process has been applied in practice to verify the correctness and feasibility of this method.