Abstract: To ascertain the varieties and characteristics of flocculent bacteria from the senage,conventional culturing techniques with flocculation rate determination and repeated enrichment were used to isolate and screen out flocculating bacteria from sewage drains. Besides,morphological observation,physiological and biochemical characteristics analysis,molecular biological identification and flocculation rate analysis were conducted on the screened bacteria. The results showed that 20 strains of flocculent bacteria were isolated by nutrient agar medium. The flocculent bacteria ZF1 and ZF18,which featured stable flocculating performance and good activity,were screened out with flocculating rate of 57.68% and 57.20% respectively,which were higher than that of the rest 18 strains. ZF1 was identified as Shigella sp.and ZF18 was identified as Pseudomonas fluorescens. Not only will the research project allow flocculating microorganism studies access to good bacteria resources,but also promise huge application potential to the studies on sewage treatment.