A method, an apparatus, a user equipment and a base station are provided for implementing location area update. In the method, the UE obtains a judgment result by determining whether there is data to be transmitted currently, when a radio access network-based location area update (RLAU) is triggered, where the data to be transmitted is one of service data and signaling data. The UE determines a second message based on the judgment result and a first message, where the first message is an original connection resume request message, and the second message carries a cause value requesting for resuming connection. The UE transmits the second message to the base station.