Abstract: A kind of phycocyanin is extracted from Chroomonas caudata Ceitler (Cryptophyta). The result of the preliminary analysis indicated that the absorption spectrum of phycocyanin has two peaks at 590 nm and 640 nm respectively. According to Glazer opinium about cryptomonad phycocyanin divided type,phycocyanin of Chroomonas caudata Geitler belongs to the cryptomonad PC-645 Ⅱ type.