ObjectiveTo understand the distribution of Pseudomonas aeruginosa (PA) in healthcareassociated infection (HAI) as well as the environment, and to evaluate their relation.MethodsBacteria in clinical samples from a hospital from June, 2006 to June, 2009 were cultured and isolated with routine method, and strains were identified by using VITEK32 system.Serotyping of PA were performed by using standard serum of PA.ResultsOf 196 clinically isolated PA, serotyping rate was 90.82% (178 isolates), the main serotypes were type G（26.02%）, E（15.31%）,F（14.29%）, B（10.21%）,H（9.69%）, and I（7.14%）, but type A, J,and K were not found; Of 25 environmentally isolated PA, serotyping rate was 96.00%（24 isolates）, the main serotypes were type G（32.00%）,F（24.00%）,B（16.00%）, and E（12.00%）.ConclusionPA isolated from patients and environment has similar serotypes, it shows that there is certain relation; Bacterial serotyping can combine bacterial detection with HAI surveillance, and can be used for clinical epidemiological investigation.