This article presents an instrumental analysis of the kinds and contents of basic amino acids contained in 9 planktonic algae specimens and a comparison between the nutritive value of amino acids in the 9 planktonic aglae and that of amino acids in prawn.Moreover, a comparison is made between contents of various planktonic algae amino acids essential to animails.It is concluded that such algae as N.Closterium., f.finutissima, C.Simplex var, CaIcitrans, P.tricornutum, Pla.Subcordiformis and S.costatum are nutritive foodstuffs.