Abstract: Objective To explore the clinical effects of ultra pulse mode of ultra pulse carbon dioxide fractional laser combined with Deep FX mode or Scaar FX mode on the treatment of patients with hypertrophic scars on face and neck. Methods One hundred and fifty-eight patients with hypertrophic scars on face and neck who met the inclusion criteria were admitted to Hunan Provincial People′s Hospital from January 2012 to January 2015. Firstly, the scar areas were cleaned and given compound lidocaine cream for surface anesthesia. Then the scar areas were treated with ultra pulse mode of ultra pulse carbon dioxide fractional laser, with energy from 150 to 175 mJ, frequency of 40 Hz, hole to hole distance of 4 mm or 5 mm, and the treatment time of each hole of 2 s or 3 s. For mild scar, Deep FX mode was added for treatment with energy from 30 to 50 mJ, frequency of 300 Hz, and density of 5%; for moderate and severe scar, Scaar FX mode was additionally used for therapy, with energy from 80 to 150 mJ, frequency of 300 Hz, and density of 3%. The above-mentioned treatments were performed per three months, totally for 3 times, 10-15 min per treatment. After each treatment, wounds were moisturized and given sun protection. Before the first treatment and 6 months after treatment of 3 times, the curative effect was assessed by Vancouver Scar Scale (VSS) and University of North Carolina Scar Scale. Six months after treatment of 3 times, satisfaction degree of patient and loss of working time were recorded. The adverse effects of whole treatment course were recorded. Data were processed with t test. Results (1) Six months after treatment of 3 times, VSS score of patients was (3.1±1.0) points, which was significantly lower than that before the first treatment [(9.4±1.8) points, t=53.096, P<0.05]; University of North Carolina Scar Scale score of patients was (1.6±0.7) points, which was significantly lower than that before the first treatment[(8.0±1.4) points, t=63.730, P<0.05]. (2) Six months after treatment of 3 times, 150 patients were very satisfied with the curative effect, 6 patients were satisfied, and 2 patients were relatively satisfied. The loss of working time of patients was 10-15 (10.5±0.3) d. (3) During the treatment, mild erythema appeared in 5 patients which disappeared without treatment; pigmentation appeared in 6 patients 2 weeks after the first treatment, and pruritus and rash appeared in 2 patients 3 days after the first treatment, which were all improved with pharmaceutical therapy. Conclusions Ultra pulse mode of ultra pulse carbon dioxide fractional laser combined with Deep FX mode or Scaar FX mode has definitely clinical effect on patients with hypertrophic scars on face and neck with few adverse effects, which is worth to popularize and apply for clinic.