Biochemical identification is mainly based on API-20NE system, supplemented by five necessary tests. The results showed that the four Acinetobacter species all met the general characteristics of Acinetobacter: negative oxidase, positive catalase, no power, negative indole, sugar-free fermentation and no nitrate reduction. In API-20NE system, the identification percentage (%ID) of 72 strains of Acinetobacter baumannii was ≥ 99.0%; The% ID of Acinetobacter calcoaceticus strain 15 is ≥ 99.0%; The %id of three strains of Acinetobacter yoelii ranged from 95.0% to 99.9%, with an average of 98.3%. The %id of six Acinetobacter lofei strains ranged from 97.0% to 99.9%, with an average of 99.4%.