The diseases of Citrus caused by Colletotrichum gloeosporioides Penz are very common.Colletotrichum gloeosporioides are found in the field mostly in summer and autumn,when the weather is hot and wet.The mainly methods to prevent the damage of Colletotrichum gloeosporioides are proper management of the field and usage of chemicals.This paper summarized the symptom of this kind of disease and the methods to prevent it.This paper also discussed the future study of Colletotrichum gloeosporioides.