Four new species belonging to the Acantholycosa-complex from South Siberia (Russia and East Kazakhstan) are diagnosed, described and illustrated: Acantholycosa kulikovi sp. n. (♀, Kazakhstan), A. sergeevi sp. n. (♂, Russia), A. sidorovi sp. n. (♂♀, Russia) and Mongolicosa lizae sp. n. (♂♀, Russia). Previously unknown females of Acantholycosa levinae Marusik, Azarkina & Koponen, 2004 and A. sayanensis Marusik, Azarkina & Koponen, 2004 are described for the first time.