[Portrait of a scientist].

The article is devoted to the analysis of scientific and social activities of academician Sergei Severin whose 110th birthday anniversary comes in 2010. Severin was a well known Russian scientist, the founder of a biochemical school in this country and organizer of the Department of Biochemistry at Lomonosov Moscow State University that he headed for 50 years! Severin belonged to a pleiad of omniscient scholars having numerous followers and disciples. This essay describes his life, creative work and scientific heritage.