目的:探讨三氧化二砷(As2O3)对H22肝癌荷瘤小鼠免疫功能的影响及实体瘤生长情况。方法: 利用流式细胞仪及改进的MTT还原法分别对正常小鼠、荷瘤小鼠对照组、荷瘤小鼠As2O3治疗组进行T细胞亚群及NK细胞活性（NKCA）的测定，并比较各组瘤重，计算瘤重抑制率。结果:肝癌小鼠荷瘤对照组与正常组比较，CD3＋，CD4＋，CD4＋/CD8＋及NKCA均明显减少（P<0.01）；低剂量及高剂量 As2O3治疗组与荷瘤对照组比较，CD3＋, CD4＋, CD4＋/CD8＋及NKCA均明显升高（P<0.05）,CD8＋无明显变化；而高剂量 As2O3治疗组与低剂量 As2O3治疗组比较,CD4＋,NKCA明显升高（P<0.05）,CD3＋, CD4＋/CD8＋无明显变化。治疗组瘤重抑制率分别为39.12%，45.74%，病理观察可见间质内大量炎症细胞浸润。结论: AS2O3 能抑制实体肿瘤的生长，提高肝癌小鼠的免疫功能，这是一值得继续研究的临床课题。

Objective： To explore the immune effects and the solid tumor growth of arsenic trioxide on experimental H22 Hepatoma-bearing mice.Methods：T lymphocyte subsets and NKcells activity were assessed by flow cytometry and improved MTT assay. Calculate the tumor inhibitory rates. Results: The percentage of CD3＋ cells and CD4＋ cells, the ratio of CD4+ cells to CD8+ cells, the activity of NK cells in the tumor control group were markedly lower (P<0.01) than those in the healthy control group. However, they were significantly higher in the tumor treatment than in the tumor control group. There was a higher percentage of CD4+ and NKCA in arsenic trioxide treatment group at high dosage than that at low dosage (P<0.05). The tumor inhibitory rates were 39.12% and 45.74% separately. A lot of inflammatory cells could be seen under optic microscopy. Conclusion：Arsenic trioxide can obviously increase the immune function of H22 Hepatoma-bearing mice and inhibit the growth of tumor body.