The present disclosure relates to a wireless communication system and to a method for connecting RRC for controlling overloads in the wireless communication system. The method includes the steps of: a mobile signal processing unit transferring an overload control message including preference priority information for overload control to a base station; the base station storing the preference priority information and receiving an RRC connection request message including service information for performing a service from a UE; the base station determining whether the service information is included in the preference priority information when receiving the RRC connection request message; and the base station transmitting an RRC connection allowance message to the UE when the service information is included in the preference priority information. Accordingly, the base station can efficiently control the overload for each service performed in the UE.