Metabolic rate, body temperature, and thermal conductance were determined in the greater long-tailed hamster (Cricetulus triton) at a temperature range of 5-36 °C. Oxygen consumption was measured by using a closed circuit respirometer. The thermal neutral zone was 39-34 °C. Within a temperature range of 5-31 °C hamsters could maintain a stable body temperature at a mean of 36.7±0.1 °C. Mean basal metabolic rate within thermal neutrality was 1.23±0.02 ml O2/g.h. Total thermal conductance was maintained within a temperature range of 5-15 °C (mean = 0.12±0.00 ml O2/g.h °C). The ecophysiological properties of the greater long-tailed hamster were: (1) a higher metabolic rate than predicted by the allometric scaling equation for eutherian mammals, but lower than that predicted for all rodents and slightly higher than predicted for cricetid rodents; (2) the body temperature was relatively low; (3) thermal conductance was relatively higher than predicted on the basis of body weight. All these characteristics are closely related to the species' life style (i.e. a burrowing, solitary, nocturnal species that feeds mainly on crop seeds and a small fraction of young crop shoots and insects). Greater long-tailed hamsters are primarily distributed in the northern Yangtse River area of China and cannot survive in extremely dr and alpine areas. We propose that the ecophysiological characteristics of the species might constrain its distribution and range extension into extreme deserts, high altitudes and cold areas.