Abstract: To understand the response of nonstructural carbohydrates (NSC) to drought stress, two-year-old Caragana microphylla seedlings were planted in four different water treatments (suitable water level, mild, moderate and serious drought stress, i.e., 80%, 60%, 40% and 20% of field waterholding capacity) for 15, 30, 45 and 60 days. The results showed that there were significant interacting effect between drought stress degree and duration on the contents of soluble sugar, starch and total NSC of leaves, stems, coarse and fine roots of C. microphylla seedlings. Under mild drought stress, the soluble sugar, starch and total NSC contents in each organ were significantly lower than those under suitable water level on the 30th day of treatment. Moreover, the soluble sugar content in fine roots and starch content in coarse roots were significantly higher than those under suitable water level on the 60th day of treatment. Under moderate drought stress, the soluble sugar content in stems and coarse roots was firstly significantly lower than that under suitable water level, and then it gradually increased. Meanwhile, compared with mild drought stress, the soluble sugar content in leaves, stems and fine roots increased while the starch content in stems and coarse roots decreased under moderate drought stress. Under serious drought stress, the starch content in each organ was significantly lower than that under suitable water level on the 15th day of treatment, and it was significantly higher than that under suitable water level on the 60th day of treatment. These results indicated that C. microphylla seedlings adapted to different drought environments by adjusting accumulation and distribution of NSC contents in different organs.