目的　研究口腔鳞癌 (OSCC)及癌前病变 (PL)中TGFβ受体Ⅱ (TGFβRⅡ )的表达。 方法　采用免疫组织化学染色SP法。结果　TGFβRⅡ在OSCC及PL中均见阳性表达。正常及单纯增生组TGFβRⅡ阳性表达见于上皮全层 ,而在异常增生组中TGFβRⅡ阳性表达仅见于粒层及棘细胞层 ,基底细胞层未见表达。在OSCC组中TGFβRⅡ阳性表达多见于癌巢中心类棘层细胞 ,癌巢周边细胞多为阴性表达。在PL组中 ,重度异常增生的阳性率最低。阳性染色强度随着异常增生程度的增加而减弱。在OSCC组中 ,随分化程度的降低 ,阳性率降低且阳性染色强度减弱。癌旁上皮的阳性率及阳性染色强度均高于癌组织。结论　TGFβRⅡ在OSCC的发生发展过程中起一定的作用。口腔癌前病变中TGFβRⅡ的表达缺乏或减弱可能是造成癌变的重要机制之一 Objective To study the expression of TGFβR Ⅱ in oral squamous cell carcinoma (OSCC) and precancerous lesions (PL). Methods Immunohistochemical staining SP method. Results TGFβRⅡwas positive in both OSCC and PL. The positive expression of TGFβRⅡin normal and simple hyperplasia group was found in the whole epithelial layer, but in the abnormal proliferation group, the expression of TGFβRII was only found in granulosa layer and spine cell layer, but not in basal cell layer. In the OSCC group TGFβR Ⅱ positive expression more common in the cancer nest center of the stratum spinocerebral cells, mostly around the cancer nest negative expression. In PL group, the positive rate of severe dysplasia was the lowest. Positive staining intensity with the degree of abnormal proliferation and weakened. In the OSCC group, with the degree of differentiation decreased, the positive rate decreased and the positive staining intensity weakened. The positive rate and the positive staining intensity of para-epithelium were higher than that of cancer tissue. Conclusion TGFβRⅡ plays a role in the development of OSCC. The lack or weakening of TGFβRⅡexpression in oral precancerous lesions may be one of the important mechanisms that cause cancer