Abstract: Objective: To observe the effects of mini-type black light lamp on treatment of plaque psoriasis. Methods: 76 patients with plaque psoriasis were treated with irradiation of mini-type black light. 20 times of therapy was counted as a course. Results: The rate of clinical efficiency was 72.37 % and 84.21 % respectively after treatment of the first and second course. No obvious adverse effects were observed during the course of therapy. Conclusion: Mini-type black light lamp has some advantages in treatment with plaque psoriasis, such as convenience, efficiency and little adverse effects.