Abstract: Brown Adipose Tissue(BAT) is quite distinct from common white one in function and structure.Its major function is to generate heat under cold stress (nonshivering thermogenesis, NST), burn excess calories for preventing obesity (diet-induced thermogenesis, DIT) and raise body temperature for combating infection, etc.. Factors influencing the amount and activity of BAT are numerous, but the important ones are body size, age,ambient temperature, photoperiod, diet, reproductive stage, and so on. Researches on BAT and NST have important significance in understanding the cold seasonal acclimatization of small mammals and in human physiology and medicine (e.g. aetiology of obesity).

Key words: micro-topography of loess plateau, plant community, species composition, quantitative characteristics, species diversity