In order to study the relationship between body status and circumstances in Eothenomys miletus,body mass and energy contents under different conditions(both infield and laboratory)were measured.The result showed that body mass and energy contents in E.miletus showed seasonal variations.Body mass and energy contents in E.miletus were higher in June and lower in March.Body mass and energy contents in the cold acclimation were decreased significantly to that in the condition of lab-breeding,indicating that temperature is an important factor to influence body mass and energy contents during seasonal changes.The change pattern of body mass and energy contents in E.miletus were related to the adaptation to the environment in Hengduan Mountainous Region.