Abstract: We analyzed the composition of the basic nutrients and amino acids, fatty acids and some trace elements as well as vitamins of ink from Sthenoteuthis oualaniensis in the South China Sea with an atom absorptiometry, gas and liquid phase chromatography as well as some general chemical methods. The results show that the contents of water, crude protein, fat and ash in the ink were 65%, 30.6%, 0.7% and 2.08%, respectively. Sixteen kinds of amino acids were found which contained seven kinds of essential and one kind of half-essential amino acids. Essential amino acid was about 39.8% of total amino acid in the ink and 46.9% of umami amino acid. The ink contained 13 kinds of fatty acids and the relative content of unsaturated fatty acid (UFA) was 64%, rich in vitamins and mineral elements such as K, Na, Ca, Mg, Fe, V_B1, V_B2 and V_E, which had significant effects on the operation of normal physiology function in human body.