Objective To research reducing capacity and identification of aerobic denitrifiers WXZ-15 and WXZ-19. Methods Four factors three levels [L9(34)] orthogonal experiment was adopted to determine the best experimental condition for reducing capacity of aerobic denitrifiers WXZ-15 and WXZ-19.The tests were conducted to study the reducing capacity to reduce nitrate in the presence of NO2-and NO3-. Partial 16S-rRNA analysis was used to identify aerobic denitrifiers WXZ-15 and WXZ-19. Results The result of range analysis showed the best experiment condition of WXZ-15 aerobic denitrifier,in which COD/N was 10,rotating speed was 160 r/min,the inital NO2-concentration was 200 mg/L,initial pH was 7.5,and that of aerobic denitrifier WXZ-19,in which COD/N was 10,rotating speed was 160 r/min,inital NO2-concentration was 50 mg/L,initial pH was 7.5. Comparing experiment showed that the TN removing rates of aerobic denitrifiers WXZ-15 and WXZ-19 were 85.65% and 45.23% respectively,using NO3-as nitrogen source. While the TN removing rates of aerobic denitrifiers WXZ-15 and WXZ-19 were 52.32% and 35.40% respectively,using NO2-as nitrogen source. Conclusion Aerobic denitrifiers WXZ-15 and WXZ-19 are Delftia tsuruhatensi and Pseudomonas putida respectively.The reducing capacity of aerobic denitrifiers WXZ-15 and WXZ-19 is strong.