In order to analyze the relationship between nitrogen and phosphorus fertilization and nostructure carbohydrate (NSC) or grain yield of oil flax,a field experiment was conducted to detect the effects of Nfertilizer and Pfertilizer application rates on the production capacity of NSC and its translation and distribution in oil flax.The results showed that the accumulation amounts of NSC in leaf increased firstly and then decreased with the increasing of the Nfertilizer rates,and increased with the increasing of the Pfertilizer rates.The content of NSC in oil flax had a negative correlation with its nitrogen (N) concentration,but had a positive correlation with its phosphorus (P) concentration.The contribution of preanthesis NSC to grain yield was 10.97%~33.92% and it was decreased when N was applied but increased when P was applied.The translation efficiency of NSC before flowers was 17.19%～41.00%,which decreased by N application rates,but increased by moderate P application rates.The NSC accumulated after the flowers made a larger contribution to the grain yield,contribution rate of NSC after flowers was 39.26%~73.68%.The NSC content of preanthesis had a significant positive correlation with the effective capsules and the yield,the correlation coefficients were 0.887and 0.667,respectively.The NSC of the postanthesis had a significant positive correlation with the effective capsules,the yield,the size of capsules and the thousand seed weight,the correlation coefficients were 0.734，0.774，0.687，0.816,respectively.