The present invention relates to a method and system for transmitting digital data while waiting for call connection and a mobile communication terminal for the same. If an originating mobile communication terminal attempts call connection, the mobile communication system searches for service subscription information of a terminating mobile communication terminal and confirms whether or not the terminating mobile communication terminal is a subscriber of a data transmission service. If the terminating mobile communication terminal is a subscriber of the data transmission service, the mobile communication system requests and receives call connection waiting information containing a plurality of digital data and matching to the terminating mobile communication terminal from a connection information providing server, and encodes and transmits the call connection waiting information to the originating mobile communication terminal. Therefore, digital data can be transmitted to the mobile communication terminal while connecting a call without separately using an additional protocol.