600 strains of Pa were typed from the sputa of patients with cor pulmonale in 8 hospitals. P6 type stoods first, accounting for 25.6%, and the types of PA and the difference in distribution of Pseudomonas from different districts and hospitals, might be used as an important parameter in the epidemiological study. 68 of 150 strains from patients with cor pulmonale contained plasmids. 60 isolates harboring plasmids colonies were hybridized with 6 beta-lactamase and 6 aminoglycoside modifying enzyme resistance gene probes. The experiments demonstrated the 3 strains isolated from patients with nosocomial infection came from one same strain and got a new resistance gene during spreading of nosocomial infection, and these isolates contained homologous sequence with OXA-2 and AAC (6')-1b probes.