To understand the connection between non-structural carbohydrates (NSC) and the supplying relationship of nitrogen and phosphorus in tree leaves, a two-year nitrogen and phosphorus fertilization experiment was conducted in Larix olgensis plantations in 11 years in Maoershan area, Shangzhi City, Heilongjiang Province. N and P treatments were set at 4 levels respectively and the N, P, soluble sugar and starch concentration of mid-crown leaves were measured at the end of August. The results showed that N appli...