The scientific worth of insect fossils is extremely high. The very first remains of insects were found throughout the third Asian expedition from the American Museum of Natural History (1923) towards the Anda-Khuduk locality. Up to now, 112 localities, in the Permian to Neogene, have been discovered in Mongolia, such as the world’s largest lagerstätten Böön Tsagaan and Shar Teg. Many of them are Jurassic minimizing Cretaceous localities Jurassic localities are considerably less numerous than Lower Cretaceous ones, which account in excess of 1 / 2 of all known localities. Paleoentomological surveys happen to be performed having a different intensity through the Joint Soviet–Mongolian Paleontological Expedition (JSMPE) and Joint Russian–Mongolian Paleontological Expedition (JRMPE) since 1970. As many as 17 expedition journeys happen to be transported out. Consequently, several thousands of insect remains representing 29 orders, 299 families, 695 genera, and 870 species were acquired. However, the systematic position of numerous forms, especially homopetrans, coleopterans, and dipterans, is not described or frequently even identified. Greater than 300 works happen to be printed around the fossil insects of Mongolia, but under 1 / 2 of the collected material continues to be described. Combined with the paleontological collections, considerable attention was compensated to paleoecological observations. To know a brief history water physiques, detailed studying and outline from the structure of sediments as well as their stratigraphy happen to be performed. It’s been says environments of ancient water physiques differed considerably from what is restored according to Recent analogues. A brand new plan of stratigraphic relationships between Jurassic and Cretaceous localities is supplied. Case study of paleogegraphic distribution of insect remains demonstrated that localities of western Mongolia belong to a new paleozoogeographic division than the remainder of its territory, that is biotically much like Transbaikalia and China.