Citrus belongs to Rutaceae, which is a wild evergreen tree with a height of 3 meters, thick and straight trunk, umbrella-shaped crown and spectacular appearance. Flowers bloom in May, white and fragrant. The fruit of 10 month is oblate and generally weighs 100- 170g, with orange color, thick skin, wrinkles, neat meat, sour taste and strong fragrance. The intact ones can be kept for 3 months. In the past, monks and nuns in the mountains all offered sacrifices to the Buddha, which was called "incense source". It can also be used as a traditional Chinese medicine formula, and has the effects of promoting digestion, reducing qi, stopping vomiting and resolving phlegm. 1980 was conducted in the breeding room of Fruit Research Institute of Sichuan Academy of Agricultural Sciences in April. The results show that citrus is a kind of nutritious fruit, with sugar content of 2.62%, acid content of 5.59%, vitamin C39. 19% and solid content of 9.5%.