Objective: To explore clinical application effects of skin distractor on the treatment of scars and to observe effects of skin distractor with different pull speeds on different parts scars of human body. Methods: One hundred and four patients with scars, conforming to the study criteria, were hospitalized in our unit from January 2014 to June 2015. Patients were divided into 2 mm/d group and 4 mm/d group according to the random number table, with 52 patients in each group. After admission, skin distractors were pasted on scars in face and neck, trunk, and extremities of patients in 2 groups, with inner edges of pasteboards close to outside edges of longer sides of scars. Skin distractors in 2 mm/d group and 4 mm/d group were pulled to scars axis direction as speeds of 2 mm/d and 4 mm/d, respectively. Pull time equals values of pull speeds divided by width of scars. Scars were resected after finishing pulling. Immediately after scars resection, skin distractors were pasted again with inner edges of pasteboards close to outside edges of longer sides of incision and removed when stitches were taken out. Scars of patients were scored by Vancouver Scar Scale (VSS), and Patient and Observer Scar Assessment Scale (POSAS) was used to record scores of patient scar assessment scale (PSAS), observer scar assessment scale (OSAS) and overall scores of patients and observers of scars of patients before and one year after scars resection. Data were processed with χ² test, independent samples t test, paired samples t test, independent samples non-parametric rank-sum test and paired samples non-parametric rank-sum test. Results: (1) Scores of all scars of patients in 2 groups before scars resection were close (with t values from -1.384 to 0.622, P values above 0.05), obviously higher than those of one year post scars resection (with t values from 11.085 to 24.835, P values below 0.01). Scores of scars in face and neck, trunk and extremities in 2 groups before scars resection were close (with Z values from -1.651 to -0.035, t values from -1.549 to 0.219, P values above 0.05), significantly higher than those of one year post scar resection (with Z values from -2.992 to -2.555, t values from 8.739 to 19.076, P values below 0.01). (2) Scores of all scars of patients in 2 mm/d group of one year post scars resection were lower than those in 4 mm/d group (with t values from -2.583 to -2.018, P values below 0.05). PSAS scores of scars in face and neck and trunk in 2 mm/d group of one year post scars resection were lower than those in 4 mm/d group (with Z values respectively -2.385 and -2.198, P values below 0.05), other scores of scars in face and neck and trunk of patients in 2 groups of one year post scars resection were close (with Z values from -1.841 to -0.363, P values above 0.05). VSS scores, PSAS scores, OSAS scores, patients′ overall scores, and observers′ overall scores in 2 mm/d groups were (4.6±0.8), (28±4), (28±4), (4.7±0.7), (4.8±1.4) points, respectively, lower than those in 4 mm/d group[(5.2±0.8), (32±4), (31±6), (5.5±1.2), (5.5±1.0) points, respectively, with t values from -3.712 to -2.105, P<0.05 or P<0.01]. Conclusions Skin distractor has better effects on the treatment of scars, and treatment effects of skin distractor in extremities pulled by 2 mm/d are better than those pulled by 4 mm/d.