six new diseases of Iongan(Dimocarpus longan Lour.)were reported in this paper,theywere:leaf blight caused by Pedalotlopsis pauciseta(Sacc)Y.X. Chen,leaf spot by Ascochytalongan C.F.Zhnag et P,K. Chi,sp. nov.,grey leaf blight by Phomopsis guiyuan C.F.Zhang ct P.K,Chi,sp. nov.,brown leaf spot by Marssonina euphoriae C.F. Zhang et P.K,Chi,sp.nov.,and leaf spots caused by Leptosphaeria longan C.F. Zhang et P.K.Chi,sp.nov,or by Lephaeria guiyuan C.F, Zhang et P,K,Chi,sp. nov,The latter5 species were proved to be new in science. Description in Latin was given for newspecies.The type specimens are deposited in the Fungal Collection of South ChinaAgr.University.