To understand seasonal dynamic of non-structural carbohydrate (NSC) in evergreen conifers, the authors analyzed the soluble sugar, starch and NSC content of leaf, branch, bark and root system of Picea mongolica from April to October. The results indicate that starch abundance in different organs of Picea mongolica reach the highest point in May, then decrease gradually and maintain at a low level from August to October. This might be reasoned that germination required starch is accumulated through photosynthesis from April to May. The soluble sugar content is slight low in May, raise gradually and reach the highest point in October. However, starch accumulated during the growth season may not account for soluble sugar increment in winter. No significant correlation is detected between Picea mongolica different organs’ starch, soluble sugar, and NSC content to monthly mean temperature and precipitation.