Applying agricultural straw residue can improve soil fertility and crop yields.For reasonable utilization of wheat straw,in this study,with local average amount of fertilizer applied as the standard,an experiment about different amount of fertilizer applied with wheat straw residue was conducted to study the N uptake and transformation of rice under field conditions.The results showed that there was no significant effect(P>0.05)when chemical fertilizer combined with wheat straw was applied on rice yield,N accumulation,N harvest index and N production efficiency compared with pure chemical fertilizer.However,the allocation proportion of nitrogen in the ear,the amount of nitrogen translocation from vegetative organs to rice ear,the rate of transfer and the contribution rate of nitrogen translocation to grain were reduced in various degree.While the nitrogen accumulation in vegetative organs was increased in various degree and nitrogen uptake after heading and the contribution rate to grain nitrogen were significantly improved(P<0.05).Considering nitrogen transportation,uptake and utilization efficiency,we suggest that in ricewheat rotation area in Northeast Sichuan the best amount of straw residue was 6 000 kg/hm2 based on 30% decrement of fertilizer.