Abstract: The aim of this paper was to put forward a reasonable thinning mode to improve the benefit of poplar-rape agroforestry management. [Method]Using poplar-rape agroforestry patterns in the Yangtze River bottomland as materials, there were three thinning treatments for the 3-year-old poplars: cutting small and holding big, cutting one for every 3-tree, cutting one for every 2-tree. The effects of thinning on poplar-rape agroforestry patterns were studied by measuring the microclimate factors, yield and quality of rape in different thinning treatments. [Result]The results showed that the air and soil temperature were lower and the humidity was higher in the control treatment, meanwhile the air and soil temperature was higher, the humidity was lower, and the photosynthetic active radiation was the largest in cutting one for every 2-tree. The rape traits in the three thinning treatments were better than the control treatment. The lowest rapeseed water content was 12.89%, and the yield was up to 215.48 g/m2, and the highest rapeseed fat content was 35.9% in cutting one for every 3-tree, [Conclusion]which indicated cutting one for every 3-tree was the best thinning mode. Path analysis showed that the microclimate had direct or indirect effect on the yield and quality of rapes.