Abstract: Five foliage diseases of principal forest trees collected from the vicinity of Kunming are reported in this paper. They are:the black leaf spot of Populus yunnanensis caused by Fusicladium tremulae; the leaf blister on Lithocarpus dealbata caused by Taphrina caerulescens the tar spots of Ilex perryana and Ilex macrocarpa caused by Rhytisma curtisii; the powdery mildew of Celtis yunnanensis caused by Pleochaeta shiraiana and the downy mildew of Celtis yunnanensis caused by Pseudoperonos pora celtidis. The symptoms of these diseases, the morphological characteristics of pathogenic fungi, their distribution and damage are described. They are newly recorded in China. The species of host plants are reported as new hosts of their pathogenic fungi.