Abstract: Objective To quantitatively analyze the effect of negative pressure wound therapy (NPWT) on inf l ammatory factors expression in Pseudomonas aeruginosa infected soft tissue wound. Methods Eighteen Bama miniature pigs were included in this study, and wounds with diameter of 50 mm were established on the back down to the muscular and infected with Pseudomonas aeruginosa. After the infection model was established successfully, wounds were randomly and equally divided into two groups:negative pressure wound therapy group and sterile gauze dressing group. Gene expression of IL-1β, IL-6, IL-8, TNF-α were evaluated quantitatively, and meanwhile, muscular tissues were collected for neutrophil quantification in different layers of tissue at day 0, 4, 8, 12 and 16. Results IL-1β expressed lower in NPWT-treated wounds compared to gauze group at day 8 after treatment(1.357±0.205) vs (2.431±0.122), P< 0.01. NPWT group showed a decreased expression of IL-6 at day 4, 8, 12 and 16day 16, (1.265±0.166) vs (1.932±0.185), P< 0.05. Expression of IL -8 increased in two groups and it was higher in NPWT group at day 8, 12 and 16day 16, (2.301±0.220) vs (1.659±0.210), P< 0.01. Expression of TNF-αwas lower in NPWT at day 8 after treatmentday 8, (0.886±0.108) vs (1.557±0.181), P< 0.01. Furthermore, histologic examination revealed that significantly increased neutrophil count was observed in the superficial layer in wound biopsies of NPWT treatment at day 4 after treatmentday 16, (11.2±1.6) vs (18.0±1.6), P< 0.01. Conclusion In conclusion, this study demonstrates that NPWT can inhibit excessive expression of inf l ammatory factors and decrease inf l ammatory reaction for Pseudomonas aeruginosa infected soft-tissue wounds, which may be one of the mechanisms of negative pressure wound therapy to reduce infection and promote wound healing.