The effects of long-term planting white clover in citrus orchard on the distribution of soil organic carbon and nitrogen in purple soil aggregates in hilly area of Sichuan province were studied to provide theoretical basis for improving soil fertility and rational fertilizer management in citrus orchards.From 2014 to 2020，a 5-year field experiment was carried out in the hilly area of northeast Sichuan province.Two treatments were set up:clear tillage in orange orchard and white clover intercropping in orange orchard.Soil samples of 0-10，10-20 and 20-40 cm soil layers were collected in March 2020 to determine the contents of water stable aggregates，organic carbon and total nitrogen.The results showed that the soil water stable aggregates of citrus orchard in hilly area of northeast Sichuan were mainly small particle size <0.25 mm，and the content of 2-1 mm particle size was the lowest.Compared with clear tillage，planting white clover in citrus orchard increased the aggregate content of 2-0.25 mm，decreased the aggregate content of >2 and <0.25 mm，and this trend was showed in different soil layers.Planting white clover significantly increased the content of organic carbon and total nitrogen in the 0-20 cm soil layers and aggregates of different grain sizes，and the contents were increased gradually with the decrease of particle size and decreased with the deepening of soil layer.Except for the grain size of >2 and 2-1 mm in 0-10 cm soil layer，planting white clover in orange orchard improved the soil ratio of carbon to nitrogen of each particle size in different soil layers.To sum up，long term planting white clover in citrus orchard can increase the content of >0.25 mm water stable aggregates，supplement the organic carbon pool and nitrogen nutrient content of purple soil，which can improve the soil aggregate structure and enhance the sustainable production capacity of purple soil.