Abstract: Under the field-grown condition, two straw residue and three nitrogen application rates were designed to investigate the remobilization of assimilation and nutrient absorption. The results showed that straw residue return and SSNM(applying nitrogen based on the timing, amount of nitrogen and values of chlorophy11 meter). can increase N, P, K content in different organs at both heading and maturity stages. Likely the relation between source and sink was harmonized under straw residue return and N management. This technique promotes carbon remobilization from culms and sheaths to grains and NSC(non-structural carbohydrate) residue in the stems at heading stage increased, and the reversed result was observed at the maturity stage. Reasons for the differences in the formation of nutrient absorption were discussed in the paper.