An apparatus and method for synchronizing the transmission of uplink signals and reception of downlink signals by a terminal in a mobile communication system is disclosed, the apparatus and method allowing a terminal to adaptively compensate for deflection generated in synchronization of a transmission channel and a fine adjustment to be made for controlling channel synchronization. A new switching point between uplink time slots and downlink time slots is determined based on a detected present switching point and a recognized uplink and downlink time slot construction, with the new switching point utilized to perform switching between a receiver and transmitter with a variable time interval. A delay may be inserted in a transmitted uplink signal to compensate for errors in the switching function.