Disclosed is an apparatus and method for transmitting information for distinguishing between a packet data service in all of a plurality of frequency bands and a packet data service of a specific frequency band from a Radio Network Controller (RNC) to a User Equipment (UE) in a mobile communication system providing a plurality of packet data services through a plurality of frequency bands, the method including the steps of starting a packet data service which the UE has joined, and transmitting indicator information to said all frequency bands, the indicator information indicating if the packet data service can be provided in said all frequency bands.