Abstract: In order to reduce the environmental pollutions of wastewater (biogas slurry) from anaerobic digested swine manure, the effects of microalgae culture on the treatment of biogas slurry were investigated. Two different ways as sterilization and non-sterilization were adopted to the pretreatment of biogas slurry. The algal growth status after inoculations and the decreases of main water quality indicators such as COD, NH3-N, TN and TP were determined. The results showed that there were significant drops in all indicators, of which the two most important ones of COD and NH3-N decreased by 85% and 55%, respectively. Therefore it is concluded that cultivation of microalgae using biogas slurry can effectively remove wastewater pollutants, and can also obtain commercially valuable microalgae cells.