Provided is a call admission control method for use in a packet based communication system, which can secure a handoff and a quality of service (QoS) by discriminating a new call and a handoff call and borrowing a shared bandwidth, a reserved bandwidth, and a bandwidth of other service according to kinds of services and their characteristics. The call admission control method includes the steps of: a) dividing frequency band into a reservation band and a shared band for communication service handoff call and multicast service handoff call, and determining whether a call admission request of users is a new call or a handoff call; b) when the call admission request is the new call, determining whether to accept the call admission request by allocating the shared band and a band borrowed from other service; and c) when the call admission request is the handoff call, determining whether to accept the call admission request by allocating the shared band, the reserved band, and the borrowed band according to services and bandwidth resources.