Abstract: Based on the consideration of ecological safety，considerable attention has been paid to the development and use of microbial flocculants during recent years and a few progresses have been made. Some aspects are reviewed in this paper，for instance，the possible mechanisms of microbial flocculation action，the factors affecting the production of microbial flocculants，the factors affecting the flocculation activity and certain achievements of compound microbial flocculants. In addition，practical applications of microbial flocculants are also introduced. Some suggestions concerning the future research work are presented.