Abstract: This study was carried out to reveal the seasonal dietary variation of striped hamster (Cricetulus barabensis ) in Kubuqi desert of Ordos semi-arid environment in 1996.The food composition was determined by checking stomach and pouch contents.The results showed that striped hamster ate more insects and seeds than other foods in spring.The food habit changed to plant leaves and seeds in summer.In autumn the food content was mainly seeds.The animal chose perennial and annual seeds alternatively between summer and autumn.This indicated that the food habit was modified by the availability of food resources and animals'need for water and energy in this arid environment.

Key words: forest type, soil, ammonia-oxidation bacteria (AOB), ammonia-oxidizing archaea (AOA), abundance, community structure.