Hynobius maoershanensis and Pachytriton intexpectatus are endemic to Guangxi Maoershan National Nature Reserve, China. Their living environments and distribution altitudes are different. H. maoershanensis is inhabited in an alpine swamp at an altitude of 2 000 m with small population size, but P. intexpectatus lives in mountain streams with gentle currents at an altitude of 1 140﹣1 800 m. This study was designed to explore the differences of digestive tracts between H. maoershanensis and P. intexpectatus, and how the 5-hydroxytryptamine cells of digestive tract adapt to their feeding habits and living environments. Anatomical, histological and envision two-step immunohistochemistry staining techniques were used. The total length, head length, body weight, snout-vent length, digestive tract length, and the thickness of mucosa and muscle layers were measured. Statistical analysis and inspection were performed using the Kolmogorov-Simirnov test, Kruskal-Wallis test and Mann-Whitney U test (Microsoft Excel 2016 and SPSS 26.0 software). Results showed that the digestive tracts of H. maoershanensis and P. intexpectatus were composed of esophagus, stomach, duodenum, ileum and rectum (Fig. 1). The digestive tract of P. intexpectatus was longer than that of H. maoershanensis. The ratios of intestine length and snout-vent length in H. maoershanensis and P. intexpectatus were 0.57 ± 0.03 (n = 5) and 0.84 ± 0.03 (n = 5), respectively. The histological structure of the digestive tracts in H. maoershanensis and P. intexpectatus could be divided into mucosa, submucosa, muscularis and adventitia (Fig. 2). There were many glands, such as pyloric glands (Fig. 2e﹣h). The thicknesses of mucosa layer in the stomach body of H. maoershanensis was the highest (712.82 ± 37.67 μm, n = 5), while that of P. intexpectatus was in the cardia (403.24 ± 55.81 μm, n = 5). The thickness of muscular layer of the digestive tract was the highest in the pylorus, with that of P. intexpectatus thicker than in H. maoershanensis. Both open and closed 5-HT cells were distributed in the digestive tracts of H. maoershanensis and P. intexpectatus (Fig. 3), while the distributional patterns of 5-HT cells along the digestive tracts were different. 5-HT cells showed the highest density in the rectum and the least density in the esophagus of H. maoershanensis. But in P. intexpectatus, the highest count was found in the duodenum but the least count in the rectum. In conclusion, the morphological and histological structures of the digestive tracts of H. maoershanensis and P. intexpectatus are similar. The ratios of intestine length to snout-vent length of both were not more than 1, which is consistent with the characteristics of the short digestive tract of carnivorous animals. The 5-HT cells in the digestive tracts of both have endocrine and exocrine functions, but the distributive patterns of these cells have their own characteristics, which may be related to their different feeding habits and living environments.