In high speed downlink packet access (HSDPA)developed by 3GPP, adaptive modulation and coding (AMC)and hybrid ARQ (HARQ)are adopted to increase throughput of downlink packet transmission. To implement AMC and HARQ, the user equipment (UE)transmits downlink channel quality information and HARQ acknowledgement, respectively, on the uplink feedback channel (HS-DPCCH).In this paper, we propose an elegant uplink power control scheme to improve reliability of uplink feedback signalling on the HS-DPCCH when UE is in soft handoff region. Simulation results show that the proposed scheme significantly improves reliability of the feedback signalling.