The present disclosure relates to a method and device for providing different services in a mobile communication system. In an embodiment, a base station sets interference influence information including information about interference of a second signal of a second system using a second TTI with regard to a first signal of a first system using a first transmission time interval (TTI). Also, the base station transmits the first signal of the first system to a terminal, and transmits the interference influence information to the terminal in a predetermined time. In a situation where different services coexist, an HARQ retransmission technique is provided for effectively overcoming a transmission failure caused by influence of interference between services.