Abstract: The main objective of this study was to investigate the effect of ultra-high pressure and water retaining agents on the quality of fresh mutton. Sodium pyrophosphate (SPP) , sodium tyipolyphosphate (STP) and soybean protein isolate (SPI) was chosed as water retaining agents. Based on single factor experiments, dehydration rate of fresh mutton products was measured which were processed by different levels of ultra-high pressure and water retaining agents. Response surface methodology (RSM) was applied and sensory quality was considered to obtain the optimal combination. It was 0.20% SPP, 0.25% STP, 5.00% SPI, 200MPa ultrahigh pressure. Under this combination, the dehydration rate was 0.57%. Model verification showed that this model could provide some guidance for fresh meat quality control.