Abstract: Zhang Fuhe, Shi Lei, Luo Min, Liu Pei, Zhou Zhongxia, Zhang Guolong, Wang Xiuli Shanghai Skin Disease Clinical College of Anhui Medical University, Shanghai 200443, China （Zhang FH, Wang XL）; Shanghai Skin Disease Hospital, Institute of Photomedicine, Tongji University School of Medicine, Shanghai 200443, China （Shi L, Luo M, Liu P, Zhou ZX, Zhang GL） Corresponding author: Wang Xiuli, Email: wangxiuli20150315@163.com 【Abstract】 Objective To assess the therapeutic effect of plum?blossom needle tapping combined with topical imiquimod immunotherapy on cutaneous squamous cell carcinoma （SCC） in SKH?1 mice, and to explore the immunological mechanism. Methods A total of 40 SKH?1 mice with ultraviolet light?induced cutaneous SCC were randomly and equally divided into 4 groups: control group receiving no treatment, plum?blossom needle group receiving plum?blossom needle tapping on all the tumors once a day,imiquimod group topically treated with imiquimod 5% cream at a dose of 1.2 g/kg once a day, combination group firstly treated with plum?blossom needle tapping on all the tumors, and after the stop of bleeding topically treated with imiquimod 5% cream at the same dose as the imiquimod group once a day. All the mice were treated for 30 days. Morphological changes of tumors in all groups were photographed and recorded every day. The tumor size was measured once every three days, and changes of total tumor volume and survival rate of the mice were compared among the 4 groups. At the end of treatment, tumor tissues were resected, and histopathological changes were compared among the 4 groups. Real?time fluorescence?based quantitative PCR （qRT?PCR） was performed to measure the mRNA of interferon?α （IFN?α）, IFN?β, interleukin?1β （IL?1β）, tumor necrosis factor?α （TNF?α） and IL?12 in tumor tissues. Results In the combination group, tumors on the back of mice grew slowly, and some even regressed. However, tumors grew fast in the control group, plum?blossom needle group and imiquimod group, and grew more slowly in the plum?blossom needle group and imiquimod group than in the control group. Before the treatment, there was no significant difference in the total tumor volume among the 4 groups （F = 0.90, P > 0.05）. After 24?day treatment, the total tumor volume significantly differed among the 4 groups （F = 5.16, P < 0.05）. The LSD?t test showed that the total tumor volume significantly decreased in the combination group compared with the control group （P < 0.01）, but no significant difference was observed among the other groups （P > 0.05）. Log?rank test revealed that survival curves significantly differed among the 4 groups （χ2 = 8.32, P < 0.05）. The survival rate was significantly higher in the combination group than in the control group （χ2 = 4.62, P = 0.03）, but did not differ between the plum?blossom needle group or imiquimod group and the control group or combination group （all P > 0.05）. Histopathological examination showed atypical cells arranged closely, a large number of tumor cells and some keratin pearls in the control group and plum?blossom needle group, few dead tumor cells in the imiquimod group, and plenty of dead tumor cells, mild nuclear atypia and increased keratinization in the combination group. qRT?PCR revealed that the relative mRNA levels of IFN?α, IFN?β, IL?12, IL?1β and TNF?α were significantly higher in the combination group than those in the control group, plum?blossom needle group and imiquimod group （P < 0.05）. The imiquimod group showed significantly higher mRNA of IL?1β than the control group （P < 0.01）, but no significant differences were observed among the other groups （P > 0.05）. Conclusion Plum?blossom needle tapping can effectively enhance the anti?SCC activity and immunological effects of imiquimod in SKH?1 mice.