In this paper, we proposed availability evaluation of network in mobile communication network that have hand off structure. Radio mobile communication network is essential hand off action to keep communication that is no discontinuance by transfer of terminal. Part by state and hand off state ago hand off by transfer of terminal and communication network is estimated performance according to the hand off rate and hand off completion rate of system. we applied MS, SM, MM communication structure in radio CORBA for network availability evaluate. System availability in mobile communication network that can repair that propose in this study uses the hand off rate and hand off completion rate of system by transfer of terminal and availability of whole system did evaluate.