Abstract:The fresh-keeping effects of compound phosphate，tea polyphenol and nisin used as single freshkeeping fluid with a certain concentration on Synechogobius hasta fillets were investigated，respectively.Furthermore，the water loss rate of Synechogobius hasta fillet was taken as the response value，and the freshkeeping effects of complex fresh-keeping fluid consisted of the three agents on the fish fillets were investigated using Box-Behnken experimental design of response surface methodology.The results showed that the sample treated by tea polyphenol fresh-keeping fluid exhibited the best sensory quality when the Synechogobius hasta fillets were treated by the three single fresh-keeping fluids，and the tea polyphenol fresh-keeping fluid was the optimal to inhibit the increases of total number of colonies and total volatile base nitrogen.The investigation of the complex fresh-keeping fluid containing compound phosphate，tea polyphenol and nisin showed the optimal formula was 0.07%tea polyphenol，1.25%compound phosphate，and 0.15%nisin in order to get the lowest water loss rate，and compound phosphate and tea polyphenol exhibited significantly effects （P＜0.05）on the water loss rate of sample.After the Synechogobius hasta fillets were treated by the optimal complex freshkeeping fluid and further stored under refrigeration（4℃）for 8 days，the water loss rate of sample was 7.68%.