Abstract: Objective To study the efficacy and safety of imiquimod 5% cream（Aldara） in treatment of flat wart. Methods Sixtyfour patients with flat wart were divided into 2 groups.Patients in groups 1 and 2 received topical imiquimod 5% cream and topical 0.025% retinoic acid ointment for 3 months,respectively.Al1 patients were followed up once each month during which the efficacy and side effects of the two drugs were recorded. Results The effective rate for the two groups was 79.4% and 73.3%,respectively,after 3-month treatment.A difference in skin lesions was found before and after treatment（P＜0.05）.No severe side effects were observed. Conclusion Imiquimod 5% cream is effective,safe,and convenient for flat wart.