Abstract: In order to study the quality changes of Penaeus vannamei during frozen storage, the prawn samples were frozen at -35 ℃ for one night after being gutted and washed, and then stored at -18 ℃ for one month. We observed the thawing loss rate and chromatic aberration to study the weight change of prawn muscle, and observed ATP content and ATP-related compounds, total volatile basic nitrogen (TVB-N) content and pH value to evaluate the prawn′s freshness change, which provides theoretical reference for prawn production and processing. The results show that the thawing loss reaches a maximum value and the L^* value peaks to 41.56 when the prawns are stored at -18 ℃ for 18 d. However, the ATP content drops by 71.78% at the first day. Hx and HxR are always stable at low levels. At day 10, K value peaks to 7.18% and remains relatively stable till day 30. TVB-N determination shows that TVB-N content does not exceed the critica1 point of deterioration at day 30. Therefore, frozen storage can maintain P.vannamei freshness and keep each physiochemical index at a low level, but will increase the thawing loss.