In order to explore characteristics of rice growth and development,photosynthetic change rules and nitrogen nutrient absorption in the ricecrayfish system under different straw returning and feeding treatment,7 200 kg/hm2 straw returning amount and no feeding (NS+NF,CK) and treatments of 12 200 kg/hm 2 straw returning amount (S) and 1 600 kg/hm2 feeding amount (F) was used to study changes of characteristics of rice growth and development,leaf photosynthetic,population canopy structure,nitrogen utilization efficiency and yield at middle and late growth stage of rice. The results showed that S+F significantly increased the yield,and the number of effective panicle,the seedsetting rate and the number of grains per tassel. The nitrogen content in rice mature plants was also significantly increased. The actual yield of NS+F treatment was 9.34 t/hm2,being the highest and 3.43%11.72% higher than that of other treatment. S treatment was mainly effective in the late growth stage of rice,which delayed the senescence of rice leaves and reduced the decrease of the intensity of root wound flow in the mature stage. F treatment increased the tiller number of rice,promoted tiller stability,significantly reduced the transpiration rate of rice,and increased the accumulation of dry matter in the mature stage of rice. NS treatment significantly increased the photosynthetic rate and transpiration rate of rice. Straw returning to the field and feeding treatment has its own advantages. In farming practice,when the amount of straw returned to the field is relatively large,appropriate feeding can supplement nitrogen for microbial decomposition of straw and plant growth.