应用体外叙利亚金黄地鼠胚胎（ＳＨＥ）细胞转化试验和免疫组化的方法，对太湖、巢湖和淀山湖水体有机污染物的致癌活性进行了分析。发现在每瓶（０．０５，０．１，０．２Ｌ）原水浓度范围内，这些有机污染物均可不同程度地诱导ＳＨＥ细胞发生形态学转化，并有一定的剂量反应关系。在典型的Ⅲ型转化细胞中ｒａｓＰ２１蛋白表达明显增高，免疫组化染色阳性，且在过度期Ⅰ、Ⅱ型转化细胞中Ｐ２１已有中等程度的表达。提示太湖、巢湖和淀山湖有机污染物具有一定的致癌活性，ｒａｓ癌基因的激活可能是其诱导ＳＨＥ细胞发生恶性转化的机制之一。 The in vitro carcinogenesis of Syrian hamster embryo (SHE) cell transformation assay and immunohistochemistry was used to analyze the carcinogenic activity of organic pollutants in Taihu Lake, Chaohu Lake and Dianshan Lake. It was found that these organic pollutants could induce the morphological transformation of SHE cells to varying degrees and have a dose-response relationship in the range of raw water (0.05,0.1,0.2L). In typical type III transformed cells, the expression of rasP21 protein was significantly increased, immunohistochemical staining was positive, and P21 was moderately expressed in type I and type II transformed cells. It is suggested that organic pollutants in Taihu Lake, Chaohu Lake and Dianshan Lake have certain oncogenic activity. The activation of oncogene ras may be one of the mechanisms that induce the malignant transformation of SHE cells.