Chestnut is a deciduous tree. Chestnut seedlings can be as high as 20 meters, and their life span exceeds 100 years. Castanea mollissima seedlings only bear fruit in 4 ~ 8 years, 15 ~ 16 enters the full fruit stage, and begins to bear fruit in 2 ~ 3 years after grafting propagation, and enters the full fruit stage in 4 ~ 8 years, which can last for more than 50 years under good management conditions. Chestnut is a deep-rooted tree species with well-developed root system, and the horizontal distribution of root system is usually 2.5 times that of crown. The flower bud differentiation of chestnut takes a long time, from June to July last year to the early growth of new shoots in the next year. Self-pollination of chestnut can get pregnant, and cross-pollination can improve the seed setting rate. The growth and development of chestnut can be divided into four periods: fertilization period, embryo formation period, endosperm absorption period and cotyledon weight gain period. It belongs to the cotyledon weight gain period from August, about 1 month. The dry matter accumulation of chestnut fruit is mainly in this period, especially in the first few days of maturity. Therefore, chestnuts must be harvested after they are fully mature, so that chestnuts have high yield and good quality.