Abstract: Objective: To assess the clinical efficacy, influencing factors and safety of frequency doubling Q-switched Nd:YAG 532 nm laser in the treatment of nevus fuscocaeruleus zygomaticus (NFZ). Methods: The data of the patients with nevus fuscocaerules zygomaticus in our hospital from June 2011 to June 2015 and treated with frequency doubling Q-switch Nd:YAG 532 nm laser alone were retrospectively analyzed, including the times of treat, the age of start to treat, the adverse reactions after treatment. Results: Of the 179 patients, the cure rate of the patients treated more than 3 times was 73.0%, which was significantly higher than that of the patients treated for 1 time 3.7% (P<0.01) and the patients treated for 2 times 16.4% (P<0.01) respectively. The age of the patients ranged from 14 to 49 years old, the effective rate (38.1%) of the patients over 30 years old was significantly lower than that of the patients from 25 to 30 years old (41.7%, P<0.01) and ≤25 years old (66.2%, P<0.01). 72(40.22%) cases had pigmentation of different degrees after treatment, which disappeared within 3 to 6 months. 2（1.11%）cases had blisters without scars left. Conclusion: Early and multiple use of frequency doubling Q-switched Nd:YAG 532 nm laser is safe and effective in the treatment of nevus fuscocaeruleus zygomaticus.  

Key words: Q-switched Nd:YAG laser, frequency doubling 532 nm, nevus fuscocaeruleus zygomaticus