A multicast communication method in a CDMA mobile communication system
which is capable of reducing a transmission power in a base station
system, and is capable of performing an efficient multicast operation for
a large number of mobile subscribers is provided. The starting of
information distribution by a multicast operation and identification
information indicating a content of the information thereof are notified
through a broadcast channel to a mobile subscriber. Further, through the
broadcast channel, information such as a spread code or the like to be
used at this time, which is necessary for actual reception of
communication data, is notified. Then, in the mobile subscriber, a
surround environment of the mobile subscriber is checked to determine the
possibility of simultaneous receiving from a plurality of other base
station systems. If possible, similar notified information is also
received from other base station systems. Thus, all kinds of information
regarding the spread code or the like to be used for receiving distributed
information are obtained.