Abstract: The effects of transglutaminase ( TG) on fish water holding capacity were investigated using tilapia fillets. The results showed that transglutaminase could be applied as an water retention agent, as the concentration of transglutaminase increased, the weight increasing yield increased and drip loss decreased.The weight increasing yield was all above 6.5% after soaking with different concentration solution, it was better than 2% compound phosphates as the control group gained 5.35%.Fish which were soaked in 0.6% TG displayed better water-retaining property, the weight increasing yield and the thawing loss after frozen 1d were 8.04% and 3.4%. Otherwise, drip loss after cooking, moisture content and water holding capacity were all observed in samples during the 40d frozen storage.Cooking loss rate and water holding capacity frozen 40d was less than frozen 1d, 10d and 20d, it indicated that quality of fish kept well during 40d frozen storage, fish were soaked using 0.6% TG could displayed the remarkable water holding capacity and improve the fish quality.