The LasR gene was amplified from the genome of Pseudomonas aeruginosus by PCR and recombined with plasmid pUCP18 reversely. The recombinant pUCP18/lasR^antisense was verified with restriction analysis, PCR and sequence and was transformed in Pseudomonas aeruginosus. The biological effect of pUCP18/lasR^antisense was detected by RT-PCR, NAD method and the assay of pyocyanin. The air tubes of rats were infected by pUCP18/lasR^antisense strain and then carried on histopathologic slide check. Expected full length LasR fragment (721bp) can be extended from Pseudomonas aeruginosus gene with PCR technology. And it is consistent with LasR gene of Pseudomonas aeruginosa covered in GenBank (NO. NC_002516). The recombinant plasmid was constructed and transformed into Pseudomonas aeruginosus sucessfully. Compared with the rats which were infected by standard strain, the bronchitis of the rats which were infected by pUCP18/lasR^antisense strain was obviously eased. It can be concluded that the antisensenucleic acid of LasR gene can depress the virulence of Pseudomonas aeruginosus and reveal a new target site for treatment.