Abstract: In a field experiment under the condition of rice straw returning, we took wheat variety‘Sumai 188’ as the material and investigated the effects of different tillage modes and nitrogen fertilization rates on wheat yield component and population quality, to provide reference for large area mechanized cultivation of wheat following rice. There were 3 tillage managements, including no-tillage, rotary-tillage and ploughing, as well as 3 nitrogen fertilization rates including 210 kg/hm2, 240 kg/hm2, 270 kg/hm2. The results showed that: the wheat yield under no-tillage was significantly higher than those under rotary-tillage and ploughing condition; the yield was improved gradually with the increase of nitrogen rates; a significant interaction effect was found between tillage modes and nitrogen rates on grain yield; compared with other tillage modes, wheat under notillage had higher grains per spike and 1000-grains weight, more tillers with lower percentage of earring- tillers, lower source- sink coordination, and better photosynthetic ability after the anthesis stage; with the increase of nitrogen rates, a consistent improvement was observed in spike number, grains per spike, tillage number, the percentage of earring-tillers, photosynthetic produce ability after the thesis stage, and source-sink coordination. These results suggest that appropriate increase of nitrogen fertilizers could improve grain yield by optimizing wheat population quality and synergistically enhancing yield components. The highest yield is achieved under the nitrogen rate of 270 kg/hm2 or 240 kg/hm2 under no-tillage mode.