Abstract: Objective：To establish a tongue epithelial carcinoma model in Sprague-Dawley rats and to study the expression of Notch1 in different phases of carcinogenesis. Methods：A total of 40 Sprague-Dawley rats were divided into four groups: A, B, C and D. Rats in experimental groups B, C and D were fed with 0.004% 4-nitroquinoline-1-oxide (4-NQO) dissolved in drinking water for 8, 16 and 24 weeks, respectively; while rats in control group A were fed with normal distilled water. Rats in experimental groupB, C and D were sacrificed at 8, 16, 24 weeks, respectively, along with 3 rats from normal group A, simultaneously. The tongue samples were dissected and detached for HE staining and Notch1 immunohistochemistry studies. Results：Different pathological changes including mild dysplasia, moderate-to-severe dysplasia, in-situ carcinoma and invasive carcinoma were observed with the advance of administration time. Positive expression rate of Notch1 in normal mucosa, dysplasia, carcinoma were 20%(2/10), 64.7%(11/17) and 84.6%(11/13), respectively(P<0.01). In normal tongue mucosa, the positive staining of Notch1 was mainly distributed in stratum basale, while it extended from stratum basale to stratum corneum as the progression of carcinogenesis. Conclusions：Notch1 promotes the carcinogenesis of tongue mocosa and its expression on membrane may play a role in tongue carcinoma.