Abstract: Objective:To clarify the species and characteristics of filamentous bacteria in sludge,flocculation bacteria were separated from the sewage drain in Jinling Hui Nationality Town,Linzi District,Shandong Province,by means of conventional culture technique. Methods:Three filamentous strains with stable flocculation performance and good activity were obtained by the determination of flocculation rate and multiple enrichment screening of the filamentous bacteria separated with potato glucose medium,wort AGAR medium and chagrin medium. Morphological identification of each strain was carried out. The impacts of each factor on the flocculation ability of the strain were analyzed by single factor experiment and orthogonal test. Molecular biological identification and flocculation rate characteristic analysis were conducted on one strain SP with high flocculation rate. Results:According to the morphological identification,SQ was a penicillium fungus,SR was a filamentous fungus of moniliaceae,and SP was identified as a Penicillium oxalicum by molecular biology. The flocculation rate of SP for 5 g/L kaolin suspension could reach 67.7% after shake cultivation in malt extract medium,pH 6.0,150 r/min and at 28 ℃ for 72 h. Conclusion:The strains such as Penicillium oxalicum separated are of certain theoretical and practical significance in research on microbial flocculant and water treatment.