In order to study the relation of digestive tract and circumstances in Eothenomys miletus,weights and length et al of stomach,small intestine,large intestine,caecum were measured in their nature environment.The total digestive tracts showed significant seasonal adjustment in wet and dry weights.Most of the measurements of the gut were tend to be larger in cold season than in warm season.The length of small intestine and caecum in E.miletus increased in low temperature,poor food quantity and propagation;the weights of the above mentioned organs of E.miletus were largest in June.As to maintain the normal physiological function in low temperature,E.miletus increased energy intake and adjusted the length of digestive tract.The changes pattern of E.miletus in different seasons were related to their microenvironment such as low latitude,high elevation,and lower average ambient temperature.This suggests that the adjustments in capacity and size of the gastrointestinal tract play an important role in their digestive strategies of E.miletus in natural environment.