To investigate the effects of C-phycocyanin(C-PC) from Spirulina platensis on erythropoiesis in mice.The colony forming uniterythroid(CFU-E) and burst forming unit-erythroid(BFU-E) were determined using micro-methycellulose culture method in vitro.The erythropoietin(EPO)-like activity of C-PC was examined using the technique of CFU-E culture of fetal liver cells in mice in vitro.Anemic mice models were established by ~(60)Co ?-ray irradiation(5Gy) and intra-peritoneal injected with benzohyarazine hydrochloride.After normal mice were intra-peritoneal injected with C-PC (50 mg?kg~(-1)) for 5d,C-PC provided the only increase in the numbers of CFU-E and BFU-E-derived colonies.C-PC exhibited higher EPO-like activity.12.5 ng of C-PC could match with EPO 1.06U.The specific activity of C-PC was 84,800 U?mg~(-1) C-PC.When anemic mice were intra-peritoneal injected with C-PC for 5d,on d10 the leukocyte,erythrocyte and hemoglobin were significant increased.