An apparatus and method for selecting a QoS in a portable communication system are provided. The method includes, when using a high quality video communication service, sending a request for the high quality video communication service to a destination terminal using a Circuit Service Data (CSD) channel, receiving a reply message to the high quality video communication service request and, when the reply message is an acceptance of an execution of the high quality video communication service, disconnecting the CSD channel and then connecting a Packet Service Data (PSD) channel, and providing the high quality video communication service using the PSD channel.