Abstract: OBJECTIVE To find out the homology between the multidrug-resistant Acinetobacter baumannii strains isolated from neonates with lower respiratory tract infection and the environmental strains and track the potential transmission chain so as to provide scientific basis for development of intervention measures. METHODS The environmental follow-up was conducted for the neonates with lower respiratory tract infection from who the multidrug-resistant A.baumannii strains were isolated from Jun 2017 to Dec 2017, the strains were identified by using 16S rRNA gene sequencing and phylogenetic tree, and the genetic homology of the isolated A.baumannii strains was analyzed by means of Eric-PCR and MLST. RESULTS A total of 207 environmental samples were collected from the neonates with A.baumannii infection, 61 (29.47%) of which were positive.The results of the detection of 16S rRNA gene homology and phylogenetic tree analysis showed that 15 strains were A.baumannii.Eric-PCR indicated that 9 genotypes were obtained, ranging between A and I.The result of comprehensive MLST analysis showed that the strains isolated from the sputum specimens of No.2 neonates, injection pump, uniforms of responsible nurses and surfaces of No.1 incubator belonged to the ST2, which were the same as the strains isolated from the computer keyboards in wards, monitor of No.3 children and hands of responsible nurses; the other genotypes were ST195, ST208, ST191, ST75, ST92 and ST235. CONCLUSION The environmental follow-up shows that the A.baumannii strains isolated from the neonates with lower respiratory tract infection have the homology with the environmental strains, indicating that effective control of environmental pollution may facilitate the control of transmission of the infections.