A bacterial strain GM6 with high capability of accumulating poly-P was isolated from aerobic activated sludge in a municipal sewage treatment plant and identified as Pseudomonas putida.This strain could grow in conditions with pH ranging from 5.5 to 8.5 and the most favorably in solution being 6.5 in pH.But its capability of accumulating poly-P peaked when pH was at 7.0.When pH was either below 5.5 or above 7.5,this capability descended distinctly.Aeration tests showed that volume of liquid did not influence much growth of GM6.But when the volume was 100 million,its P removing effect was the best and while the volume is over 150 ml,the effect became less.The optimal temperature for its growth was 27℃.When the temperature was either lower than 5℃ or higher than 37℃,it grew slowly and its P removing effect was poor.The optimal temperature for its phosphorus removal was 20℃.After GM6 incubation in synthesized sewage,LB,YG and MOPS medium for 24 hours, phosphate concentration in the liquid media declined sharply,showing a phosphate removal rate ranging from 63% to 96.6%, which were significantly higher than that of E.coli.Its phosphate accumulating capacity was also investigated aerobically in media LB,YG,MOPS and synthetic wastewater.The results show that the total phosphorus in the GM6 cells harvested from four media was in the range of 6.80%～9.32% while that in the E.coli cells was in the range of 0.98%～2.31%,indicating the former had a higher level of phosphorus accumulation.Strain DM6 showed the characteristics of a typical phosphate accumulating organism as it displayed apparent phosphorus accumulation and release in a SBR process.Its phosphate release and accumulation rate was 4.5 mg L^-1 h^-1 at the end of anaerobic stage and 2.73 mg L^-1 h^-1 at the end of subsequent aerobic stage, respectively.