This paper is the result of an analysis of a very large collection ol lichens (about 3500 herbarium specimens), sent me by various persons. T. Rabotnov sent the largest lichen collection, gathered in the taiga zone of the Yakutsk ASSR in 1931, 1932 and 1934. Many lichens were gathered in Verkhoyansk District by M. Yarovoy in 1935. Considerable collections were sent by Sheludyakov from Tatin District (1934) and from the Indigirka River basin (1935-1936). L. Parkhova also sent her collections of 1935 and 1936 from the Indigirka River basin. A very valuable collection from the Bulun District was received from B. Gorodkov and B. Tichomirov (1935) as well as from L. Parkhova (1937) and N. Karavayev (1938). Material from Sakharir District was received from N. Prakhov (1935). A large collection of lichens from the Vitimo-Olekmin (Evenky) National Region was sent by N. Savich. My own small collection gathered in the Baikal area (Aug. 3 to Aug. 6, 1937) contains a number of interesting species and supplements that of K. Rassadina. The data on the northern part of the taiga zone and the polar region within the borders of the Yakutsk ASSR, which are among the poorly studied region, in respect to lichenology, are of great interest. They substantially supplement our knowledge of lichen distribution in the tundra and forest-tundra zones and in some cases change the existing notions. In this paper a number of new species and forms are described. Some of the species are new for Asia. Only the first part of the paper can be printed now, because of lack of space; the continuation will follow in the next number of this journal. The author wishes to express his gratitude to all persons who have sent him their collections All herbarium specimens, presented below have been included in the lichenological herbarium of the Institute of Botany of the Ukrainian SSR Academy of Sciences