Abstract: In order to provide technical supports for keeping tuna fresh for long-time transportation, the effects of three preservation agents, chitosan, tea polyphenols and potassium sorbate, on the preservation of tuna dorsal muscle during frozen storage were studied in this paper by determining the K value, TVB-N value, met-myoglobin content and chromatic aberration. The results showed that all the three preservation agents, potassium sorbate, chitosan and tea polyphenols, played positive role in keeping tuna meat fresh, and the best concentrations of them were 7 g/L, 15 g/L and 6 g/L, respectively.