A method for processing a synchronous message in an asynchronous mobile communication
system including an asynchronous mobile station and an asynchronous radio network,
comprises the steps of: when a synchronous core network is interlocked with the
asynchronous radio network, generating a system information block based on a header
information provided from the synchronous core network; formatting the generated
information block into a system information message; and transmitting the system
information message to the asynchronous mobile station via a channel.