Abstract: Mulberry fruit sclerotiniose is the major fungal disease and becomes a serious threat to mulberry production. It often occurs in mulberry field of Guangzhou areas. And the harmful symptoms show that the major disease may change from mulberry sorosus hypertrophic sclerote disease to mulberry sorosus parvulling sclerote disease. In order to identify the pathogens of this disease，its morphological features were identified and the results showed that the suface of sclerotium had lots of conidia with some conidiophores and there were full of intersecting hyphae inside. When cultured on PDA media，a white and translucent zone was formed around the sclerotium. Moreover，the ITS conserved sequences of mulberry sorosus parvulling sclerote were analyzed and the results showed that the pathogen of mulberry sorosus parvulling sclerote disease was Ciboria carunculoides.