Objective To investigate the efficacy and safety of 308-nm excimer laser compared to high-intensity ultraviolet radiation for the treatment of active localized vitiligo,and to observe changes in skin lesions before and after the treatment by confocal laser scanning microscopy.Methods Sixty patients with 203 skin lesions of active localized vitiligo and were enrolled into this study,and the vitiligo disease activity (VIDA) score of these patients ranged from 2 to 3.We selected more than 3 skin lesions from a same anatomical site of each patient,one of lesions served as a control and the other skin lesions (≥ 2) were randomly treated with 308-nm excimer laser (laser group) or high-intensity ultraviolet radiation (ultraviolet group).The treatment was conducted twice a week for 25 sessions,and a 3-month follow-up was performed.Results A total of 48 patients with 169 skin lesions completed the trial.The marked response rate was significantly higher in the laser group [66.15％ (43/65)] than in the ultraviolet group [44.64％ (25/56),x2 =8.28,P ＜ 0.01].The patients with a VIDA score of 2 showed a significantly higher marked response rate [67.69％(44/65)] compared with those with a VIDA score of 3 [44.64％(25/56),x2 =6.80,P ＜ 0.01].During the 3-month follow-up,no relapse was observed.Confocal laser scanning microscopy showed that the number of inflammatory cells increased at the dermal-epidermal junction of the intra-and extra-marginal lesional skin.After treatment,the number of inflammatory cells markedly decreased and returned to normal level in lesions.Conclusion Both 308-nm excimer laser and high-intensity ultraviolet radiation are effective in the treatment of active localized vitiligo,but the 308-nm excimer laser shows a more rapid onset of action and a better therapeutic effect.