Abstract: Grass carp ( dorsal meat, belly meat and red meat) were used as the research object, the effects of spring, summer, autumn and winter on the content of free amino acids and the contents of nucleotides in different parts of grass carp were studied by high performance liquid chromatography ( HPLC) and automatic amino acid analysis. The results showed that the percentage of flavor amino acids of the total free amino acids in dorsal grass carp meat the data was 27.79%, 13.92%, 26.99%, 36.82%, respectively. In belly meat the data was 30.68%, 13.98%, 25.34%, 32.85%, respectively. In red meat the data was34.32%, 24.88%, 31.45%, 39.09%, respectively.The lower temperature caused higher the percentage of amino acid content.K value of dorsal grass carp meat were 6.77%, 21.82%, 20.11%, 1.80%, respectively. In belly meat the data was 7.86%, 27.02%, 23.81%, 2.85%, respectively.In red meat the data were 30.57%, 58.04%, 54.08%, 12.72%, respectively. The lower temperature caused, the better the freshness.At the same season, flavor amino acid content was the lowest and freshness was the worst in red meat.Thus, the best food period of grass carp is winter and spring, the grass carp have a better taste and freshness.