A method for re-transmitting data or control information in a radio link control layer relates to determining whether re-transmission will be ended by comparing a number of transmission with a critical value when the transmission of data or control information has successively failed. The retransmission cycle is comprised of the steps in the order of transmitting information, checking the transmission failure with exit, and counting the transmission number with exit. Therefore, the present invention makes any transmission be checked and prevents wasting radio resource which can occur in re-transmitting data or control information in UMTS mobile communication system.