Objective To investigate the effects of negative pressure wound therapy (NPWT) on the expression of EDA+ FN in granulation tissues of human diabetic foot wounds.Methods Forty patients with diabetic foot wounds fitting the inclusion criteria,admitted from Jan.2014 to Jun.2016,were randomly and equally apportioned to receive either NPWT or conventional gauze therapy (control) for 14 days.Granulated tissue biopsies were collected before (0 day) and after (14 day) treatment in both groups.All biopsies were subdivided into two parts.One part was preserved in 4％ paraformaldehyde for immunocytochemical staining of EDA+FN,and the other part was stored at-80 ℃ for Western blotting and PCR analysis of EDA+FN.Results The immunohistochemical analysis revealed that the mean area density of EDA+ FN increased in both NPWT group and control group at day 14 relative to day 0,but the change value of mean area density was higher in NPWT group than in control group (P＜0.01).Western blotting showed that the relative protein levels of EDA+FN increased in both NPWT group and control group at day 14 relative to day 0,but the change value of relative protein levels of EDA+FN was higher in NPWT group than in control group (P＜0.01).The real time PCR analysis demonstrated that the relative mRNA levels of EDA+ FN increased in both NPWT group and control group at day 14 relative to day 0,but the change value of relative mRNA levels of EDA+ FN was higher in NPWT group than in control group (P＜0.01).The results demonstrated the higher protein and mRNA levels of EDA+FN in NPWT group than that in control group.Conclusion NPWT obviously enhances EDA+FN expression in granulation tissue of diabetic foot wound,as a result promotes wound healing.