Abstract: Through many years of hard work by all members of the department of entomology about 12,000 butterfly specimens were collected from Yunnan province and its neighbouring regions.Besides a few of them are waiting for identification (new species of new subspecies),about 432 species belonging to 188 genera in 11 families have been preliminaryly determined.This paper deals with the scope of the fauna and geographical distribution of butterflies in Yunnan.It has three parts:The first part have discussed preliminarily the problem of the butterfly fauna of Yunnan based on the materials in hands at present.in order to explain the character of the Yunnan butterfly fauna,we classified the data quantitatively according to statistic procedure.As a whole the results show that about 74.42% of them are Oriental species.These are the main or majority part,about 14.19% of the species we collected are transitional or over leap-regional species.Only 11.4% of these species are Palearctic species.and analysed the belongingness as well as percentage of Yunnan butterflies in Zoo-geographical division into districts of China.The second part have discussed the characteristics of the distribution of Yunnan butterflies (1,the character of vertical distribution.2,the transitional character of the distribution.3,the character of distributional difference on the different sloping direction.) The last part have discussed the obvionus differences of the fauna constitution of various areas,according to the occurrence and distribution of butterflies characteristics,together with the physical geography,landform,climate and vegetation of the place,and divide these into 3 different types of regions as the following:Ⅰ,The lower mountainous north tropical rain forest and monsoon forest subregion (about under 1,500 M.);Ⅱ,The middle mountainous subtropical evergreen broad-leaf,mixed forest and coniferous forest subregion (about range 1,500-3,000 M.);Ⅲ,The high mountainous temperate zone of coniferous forest subregion (about range 3,000-4,600 M.)