Hymenoptera is one of the largest insect orders, with a world fauna of 155.5 thousand species in 8423 genera from 94 extant families, a Palaearctic fauna of 50–60 thousand estimated species, and a Russian fauna of more than 15 thousand estimated species in more than 1500 genera from 78 families. The modern classification of Hymenoptera is given. The first volume treats the sawflies (13 families, 170 genera, 1546 species), wasps (15 families, 253 genera, 1695 species), ants (1 family, 44 genera, 264 species) and bees (6 families, 66 genera, 1216 species) which together, in Russia, comprise 4721 species in 533 genera. The sections for each of the 35 families include characteristics, number of taxa, references, and an annotated catalogue of the genera and species recorded from the fauna of Russia. For each valid genus the type species, synonymy, short characterization, and number of species are given. For each valid species the synonymy, known host plants, hosts or prey, and distribution (in Russia and general) are provided. The book is illustrated using geoschemes for Russia, Europe, and China. The large bibliography helps to assess the level of study of each family. The index of scientific names of Hymenoptera (more than 16000 names) will be useful for taxon searching.