Objective To explore the effect of the skin tension reduction device on reducing scar formation after excisional surgery of hypertrophic scars and keloids. Methods Total 10 patients with hypertrophic scars and keloids were enrolled in this study. All of them received excisional surgery. Total 10 patients were involved as a self control study with part of wound treated with tendon reduction device, the other part with no treatment as control. All patients were observed for scar formation at surgical wound sites for 3 months post-surgery. Scar width and Vancouver scar scale were used as the parameter to quantify the differences between two groups. Results Compared with control group, the postoperative scar in tension reduction group was narrower in scar width and lower in the Vancouver scar scale scores with statistical significance （P〈0.05）. Conclusion Application of the skin reduction device can efficiently inhibit wound tension induced scar formation at post-surgery sites with significant reduction of scar width and hyperplasia after excisional surgery of hypertrophic scars/keloids.