目的　探讨增强光动力学疗法(PDT) 治疗恶性肿瘤疗效的有效途径。方法　80 只昆明种小白鼠于皮下接种小鼠肝癌细胞,待肿瘤长到6 ～8 mm ,随机分为先化疗后PDT、先PDT 后化疗、单纯PDT、单纯化疗和空白对照共5 组,每组16 只。化疗方法为腹腔注射5氟尿嘧啶75 μg/g ;PDT 方法为经尾静脉注射血卟啉单醚20μg/g 后3 h 以能量密度135 J/cm2 的铜蒸气激光照射肿瘤部位。结果　采用不同治疗措施的4 组小鼠瘤体缩小,而空白对照组小鼠瘤体迅速增大,各治疗组与空白对照组比较,差异均有显著意义( P< 0-05) 。各治疗组中以先化疗后PDT 组瘤体缩小尤为显著,与其他3 组比较,差异有显著意义( P< 0 .05) 。结论　PDT 和化疗均有抑瘤效应,两种方法联合运用可提高对小鼠移植瘤的疗效,而先化疗后PDT 治疗的疗效优于先PDT 后化疗。 Objective To explore effective ways to enhance the efficacy of photodynamic therapy (PDT) in the treatment of malignant tumors. Methods Eightty Kunming mice were subcutaneously inoculated with hepatocarcinoma cells in mice. After the tumors grew to 6-8 mm, they were randomly divided into five groups: PDT after chemotherapy, PDT after first chemotherapy, PDT alone, chemotherapy alone and blank control. Group 16 only. The chemotherapy method was intraperitoneal injection of 5-fluorouracil 75 μg/g. The PDT method was performed by intravenously injecting hematoporphyrin monoether 20 μg/g 3 h after irradiation with a copper vapor laser with an energy density of 135 J/cm2 to irradiate the tumor site. RESULTS: The tumors of the 4 groups of mice treated with different treatments were reduced, while the tumors of the control group were rapidly increased. The differences between the treatment groups and the blank control group were significant (P < 0-05). The reduction of tumor size in the PDT group was particularly significant in each treatment group compared with the other three groups (P < 0.05). Conclusions Both PDT and chemotherapy have antitumor effects. The combination of the two methods can improve the efficacy of transplanted tumors in mice. The efficacy of PDT after chemotherapy is better than that after PDT.