Abstract: Objective:Comparative studies on the anti-inflammatory and uvioresistant activity of phycocyanin and phycoerythrin in Nostoc sphaeroides Kutzing were developed in vitro. Methods:Raw264.7 cells induced by LPS were used to evaluate the anti-inflammatory activity through detecting NO and TNF-α secretion. NIH-3T3 cell damaged by UVB was used to evaluate the uvioresistant activity. Results:Raw264.7 cells induced by LPS secreted NO and TNF-α extremely significantly(P<0.01),and phycocyanin and phycoerythrin extremely significantly reduced the level of NO and TNF-α secretion(P<0.01). Phycoerythrin was more effective than phycocyanin on the ability of NO secretion inhibition. And phycocyanin was more effective than phycoerythrin on the ability of TNF-α secretion inhibition.UVB 4000 mJ/cm²inhibited the viability of NIH-3T3 cells successfully,but phycocyanin and phycoerythrin showed no protection efficacy on UVB induced cells damage.Conclusion:Phycocyanin and phycoerythrin shows significant anti-inflammatory activity,but there is no protection efficacy on UVB induced cells damage.