The biochemical components of the mussel tissue, cultured on the raft were estimated. The range of variation in the content of moisture, protein carbohydrates, lipid, organic carbon and ash were 66.8-90.1; 46.2-67.4; 11.7-18.6; 2.9-7.4; 19.5-34.2 and 3.1-21.2% respectively. Major biochemical constituents were found to be influenced by phytoplankton abundance and were also found to vary with maturation and spawning cycle. The caloric potential in the raft- grown mussel varied from 3.33 to 4.9 K cal. g^-1. The maximum value of total energy was found to coincide with higher values of protein, indicating significant contribution by protein to the total energy. The relationship between biochemical constituents and spawning cycle is discussed.