To investigate the relationship between food habits and digestive tract morphology, the lengths of gastrointestinal tracts of six species of rodents with different food habits were compared. The results showed that the strict herbivores, Microtus brandti, had the largest large intestine and ceacum, and the tracts of the other five granivorous/omnivorous species (Spermophilus daurica, Phodopus robovskii, Cricetulus barabensis, Cricetulus triton, Meriones unguiculatus) varied to different extents depending on the proportions of seed, vegetative and animal foods in their diets. Small intestine lengths did not reflect diet fiber content for these six rodent species and stomach lengths in granivorous/omnivorous rodents were not larger than herbivores. Our results suggest that the hind gut is more important for herbivorous than for granivorous/omnivorous rodents and could be a relative reliable indicator for food habits, however, small intestine is not a good indicator for food habits. This study also showed that there is no direct relationship between life history traits and gut morphology in these six rodent species, although more life history traits should be considered.