The abundance of the Mongolian butterfly fauna is conditioned by the natural landscape diversity, here the fauna of Central Asian desert is linked with southern foothills and montane fauna of the great mountain systems of Central Asia: Altai, Hangayn, Hentiyn and Hingan. Taking into account the large area of Mongolia and large number of species occurring there, the book contains figures of numerous type specimens (about 70 % described from Mongolia), including many Lycaenidae, Nymphalidae and Parnassiusspecies group taxa. In total the book contains information on 279 species (over 800 species and genus group taxa) occurring in Mongolia. The bibliography section consists of 601 entries. This book is unique since all the largest known Mongolian collections of butterflies in many countries were studied. The plates figure the most important and interesting examples from first known (1854) to those collected in 2009.