Abstract: 5 mice of each kind were dissected to understand the difference of the digestive system between Rattus norvegicus and Cricetulus triton. The results showed that there had many differences between the two kind’s mice in the length and structure of the organism in digestive system. The average esophagus length against body length ratio of Rattus norvegicus was 0.873 times to that of Cricetulus triton; the average stomach （no content） weight against body weight ratio was 0.462 times to that of Cricetulus triton. The ratio of the average small intestine length, large intestine length and cecum length to body length was 1.557, 0.383 and 0.283 times that of Cricetulus triton, respectively. The liver weight to body weight ratio was 1.190 times to that of Cricetulus triton. The differentiation of the two kinds of rats for food quality selection also showed obvious difference. Cricetulus triton was more dependent on plants while the food selection of Rattus norvegicus was extensive.

Key words: Rattus norvegicus, Cricetulus triton, digestive system, comparison