Abstract: The contents of trimethylamine (TMA) and the total volatile basic nitrogen (TVBN) were determined in four species of fresh witer-fish and in two species of sea-fish during decomposition stages. The results showed that the contents of TMA in fish highly correlated with TVBN and the contents of TMA index can evaluate not only the freshness of sea-fish, but also fresh water-fish. This paper also discussed the possibility of evaluating freshness of the two kinds of fish by TVBN/TMA (%) .

Key words: Ereshness of Fish Trimethylamine Total Volatile Basic Nitrogen/Trimethylamine