Objective To explore the preparation of a rat model of pneumonia model induced by Pseudomonas aeruginosa(PA) using different methods,and to lay the foundation for further studies.Methods 48 SD rats were randomly divided into 4 groups:the control group (A),the intratracheal injection group (B),the trachea cannulation group (C) and the intranasal inoculation group (D).After intervention with different treatment modalities,the body weight,temperature,white blood cell count and lung pathological changes in the rats of all groups were detected at 5,10,15 days.Results 1.The behavior,body weight,temperature,leukocytes and pathological inflammatory changes of the lung in rats of the model groups were significantly different from that of control group.2.Pseudomonas aeruginosa was detected in rats of all the model groups,but the control group was negative.Conclusions Rat model of Pseudomonas aeruginosa infected pneumonia can be successfully established by intranasal inoculation.This method can avoid the inflammatory interference from operation,and is simple and suitable for popularization.