40 samples of soybean(Glycine max(L.) Merr.) in field were took out to observe their root morphology at vegetative and pod stage respectively.Meanwhile,the drought tolerance of these varieties were tested at vegetative stage by cultivated in pots and their root morphological and physiological traits were researched.The results show that soybean root morphology varies in the two stages or in the same stage but in different conditions.There were evident and extensive genetic variations in the root morphological parameters among varieties with different water applying,including total root length,root volume,root dry weight,root reductive activity,root total absorbing area and root active absorbing area.There was also significant difference response in root traits among varieties with strong drought tolerance and weak drought tolerance.Therefore the research provides a new way for soybean breeding improvement by selecting root traits.