This paper proposes an efficient radio resource allocation (RRA) mechanism in multirate mixed-size WCDMA cellular systems. The proposed RRA mechanism deals with power and rate allocation for non-handoff and handoff users separately. For non-handoff users, RRA mechanism use a novel multi-qualify balancing power algorithm and mutirate removal algorithm to meet a common balanced signal quality for all cells. Also, for soft handoff users, RRA mechanism has a joint power and rate allocation (JPRA) algorithm to determine an appropriate allocation of transmission power and service rate for multirate soft handoffs. Via the JPRA algorithm for soft handoff, the system can achieve power balancing among cells. Simulation results show that the JPRA algorithm has better cell’s service coverage and higher system capacity. Categories and Subject Descriptors: C.2.1 [Network