Abstract: The highly effective denitrification and phosphorus removal bacteria was screened from activated sludge, it was classified and identified too. At the same time, the effects of pH and inoculation amount on the growth were studied. Getting one strains by phosphorus enrichment culture, and PHB and 16S rRNA staining, and carrying out the study of nitrogen and phosphorus removal rate, the morphological and physiological and biochemical experiments. A highly efficient nitrogen and phosphorus removal bacteria was screened. The strain was able to grow in pH 5~10, pH7 was the best. The best inoculation amount to the growth was 10%. The rates of nitrogen and phosphorus reached 78.3%, 87.8%. The strain can remove nitrogen and phosphorus at the same time, and it can identified as Lactobacillus genus by morphological observation, physiological and biochemical test, and 16S rRNA gene sequence analysis and construction of phylogenetic tree.