The matters of red clover cultivation and breeding in Russia and Siberia from 1908 to 2015 were studied. There were developed new diploid- and tetraploid-based red clover varieties by using modern breeding methods such as induced mutagenesis, polyploidy, polycross method, ecological breeding and selections. The new varieties of early and late types are distinguished by winter hardiness, high productivity, and resistance to extreme environmental conditions of Siberia. The use of native varieties in the heterosis breeding of red clover allows developing diploid-based, winter-hardy and late-ripening high-yielding cultivars SibNIIK 10, Rodnik Sibiri, Atlant. The collection sample N 880 (USA) served as a basis for developing the cultivar Ogonek by the method of selection by correlated traits. By the method of ecological breeding (within the CBT Program “Klever”) were developed the eight genotypic mixtures of different maturity and ploidy. A new tetraploid-based, early-ripening, high-winter-hardy red clover cultivar Pamyati Lisitsyna has been developed, which exceeds the standard in dry matter yields for two cuts in total by 17 per cent. Resulting from the combination of mutagenesis, polyploidy, hybridization and selection methods, a tetraploid-based, early-ripening, two-cut cultivar Meteor was for the first time developed in Siberia. The yield of green mass for two cuts of this cultivar can be up to 70 t/ha. The use of modern breeding technologies makes it possible to highly effectively realize the genetic potential of red clover when developing new varieties under extreme conditions of Siberia.