[en] An attempt to distinguish the main periods of uranium ore formation that have taken place in the geological history of the globe is made. Based on available ore formation age determinations, six uranium epochs have been recognized: Middle Proterozoic, 2200-1700 m.y., Upper Proterozoic; 1150-920 m.y.; Early Paleozoic, 550-500 m.y.; Permian, 250-190 m.y.; Cretaceous, 107-88 m.y.; and Tertiary, 23-4.5 m.y. No uranium deposits are known to be formed during Archaean. The oldest uranium ore deposits were formed in Africa (2100 m.y.) which are primarily due to the earliest transition of the earth's crust evolution from sea to continental conditions of sedimentation in this part of the earth's crust. The relation of uranium epochs to orogeneses is discussed and also periods of major uranium-bearing rock formations. The essential part of uranium deposits was formed during the Proterozoic uranium epochs in contrast to ore deposits of other mobile metals such as Mg, Mo, Cu, Sb, Pb, Zn and Hg. (author)