Abstract: With the different parts of grass carp meat (dorsal meat, belly meat, red meat) as research objects, changes of water soluble compounds in fresh samples and frozen samples was studied by the HPLC and Amino Acid Autoanalyzer. The results showed that ATP-related compounds, freshness and free amino acids were different in different parts meat which was fresh or frozen. K value of fresh dorsal meat, belly meat, red meat were 1.82%, 2.71%, 7.38%, respectively, it had no obvious difference after in the refrigerator of-18℃ for48 hours on dorsal meat and belly meat, while it increased slightly on red meat. The amounts of total free amino acids (TFAA) in dorsal meat and belly meat were higher than red meat, and the amounts of aspartate and glutamate in dorsal meat and belly meat were significantly lower than those in red meat, histidine content was significantly higher than that of red meat. After frozen, the TFAA of dorsal meat and belly meat were increased, but it was decreased of red meat. The influence of frozen on freshness and taste of red meat in grass carp meat was higher than dorsal meat and belly meat, which should paid special attention in the grass carp frozen and processed.