In the context of the problems of oil and gas content in the Late Precambrian and Phanerozoic structural-formational complexes of the ancient Siberian Platform, which is a part of the North-Asian craton, the materials available are analyzed and the most important events in its development are characterized. The following two major blocks are distinguished in the platform basement within the boundaries which are determined according to common definitions of a platform: - eastern block, with Archean - Early-Proterozoic basement; and - western, with the basement dated as pre-Baikalian (up to 850 Ma). The Baikal-Taimyr lineament is supposed to divide the above mentioned blocks. The western block cover is shown to be composed of the uppermost deposits of Paleozoic and Late Precambrian, whereas that of the eastern block - of the whole Late Precambrian, Paleozoic, and, partly, Mesozoic deposits. The folded margin of platform had ultimately developed by the end of Hercynian diastrophism in the west and SW, and during the Pacific (Cenozoic) folding in the NE and SE. Therefore, the folded margin of the ancient Siberian Platform is of different ages, and with, respectively, different ages of its boundaries. Analysis of the Late-Precambrian - Paleozoic formations and formation series shows that formations belonging to platform cover can be traced throughout its folded margins to the ophiolite systems located deep within mobile areas (such as the Yenisei Ridge, Taimyr, Baykit, Muya zone, Mongolo-Okhotsk belt, Kolyma loop, etc.), being very similar to the former. Assuming that ophiolite systems outline the craton margins, a conclusion is made that the platform is only a part of the craton and does not spatially coincide with it. It is proved that the results of analysis must be taken into account in complex oil and gas prospecting studies.