A method of performing direct communications in a network of a wireless communication system, the method comprising configuring a first communication device to enter a direct communication mode by transmitting a first mode configuration information according to a mode change information; and configuring a second communication device to enter the direct communication mode by transmitting a second mode configuration information according to the mode change information; wherein the first communication device and the second communication device respectively have a first radio resource control (RRC) connection and a second RRC connection with the network.