A method for entering an idle mode, which is used in a Worldwide Interoperability for Microwave Access system, comprising: during the procedure of a terminal enter to idle mode from active mode,, an paging agent of the terminal sending mobility restriction parameters of the terminal to a mobility restriction parameter storage network element; the mobility restriction parameter storage network element saving the mobility restriction parameters; the mobility restriction parameter storage network element being an anchor paging controller, or an anchor authenticator, or a function entity including a function of the anchor paging controller and a function of the anchor authenticator. to save the mobility restriction parameters of a terminal when the terminal enters an idle mode may be achieved by using the method of the present invention, so that a mobility restriction judgment is performed to the terminal in the subsequent process procedure, and the problem of erroneously allowing the terminal to quit from the idle mode and enter an active mode or to update its location when the terminal is in the non-authorized regions can be avoided.