Biogeography of the leaflaopper subfamily Stegelytrinae Baker is studied based on an analysis of geographical distribution of this subfamily worldwide using a cluster analysis of the zoological distribution of areas of endemism as well as the phylogeny of representatives of this subfamily. Results show that the Stegelytrinae mainly occur in the Oriental Region and in the Mediterranean area of the Palaearctic Region, and this extends to the east side of both Wallaee＇s and Weber＇s lines. Eleven areas of endemism of this subfamily are recognized. The proportions of endemic taxa in different areas of endemism are generally very high in comparison with other leaflaopper groups, but distinct differences could be found among the different areas of endemism of Stegelytrinae. This subfamily is most intensively diversified in the Indochina Peninsula （INCN）. This is the stegelytrine distribution center, having the highest biodiversity at both genetic and species levels. The dendrogram of endemic areas of Stegelytrinae constructed using cluster analysis of the zoological distribution of Stegelytrinae at generic level shows the endemic areas of Stegelytrinae can be divided into 4 large groups. Relationships among different endemic areas of Stegelytrinae correspond largely to the geologic history of related areas, which indicates that the evolution and vicariance of this subfamily have been closely related to the history of continental drift and climate changes. It is deduced that the presumed monophyletic Stegelytrinae originated in the Oriental Region after North America had separated from Eurasia; this is the case in the monophyletic genera group which is supported by the lateral frontal sutures extending dorsally well beyond the corresponding ocellus. In addition, two expanding traces of the Stegelytrinae are presumed, which remain plausible explanations for the dispersal of Stegelytrinae： （1） New Guinea （and probably （＋ Australia）） - Kalimantan - Sumatra - Malay Peninsula - Indochina Peninsula - Ce
