Chlorella sp. , Scenedesmus sp. and Spirulina sp. were inoculated to two kinds of turtle breeding wastewater. One kind of wastewater discharged after preliminary treatment by a sedimentation tank(taken from a breeding plant in Wuwei County, abbreviated as WW wastewater), and the other kind of wastewater discharged without any treatment(taken from a breeding plant in Dayangzhen, abbreviated as DY wastewater). The growth feature and nitrogen and phosphorus removal characteristics of three microalgae were studied and the purification ability of three microalgae was compared. Results show that three microalgae has different growth feature in two kinds of wastewater. The cell density and biomass accumulation of three microalgae are higher in DY wastewater than in WW wastewater. The highest biomass accumulations of three microalgae in DY wastewater are 0. 26 g/L, 0. 28 g/L, and 0. 20 g/L respectively. The effects of different microalgae on the removal of nitrogen and phosphorus from wastewater are different. TN can be easily removed by Scenedesmus sp. with the highest removal rate of 93. 65%, TP can be easily removed by Chlorella sp. with the highest removal rate of 99. 46%, and NH^{+₄-N can be easily removed by Spirulina sp. with the highest removal rate of 98. 79%.}