Six Siobla species are revised, including the following new synonymies: S. rufoscapa Wei, 2002, syn. nov., synonymized by S. villosa Malaise, 1931; S. tuberculatana Wei, 2002, syn. nov., synonymized by S. malaisei Mallach, 1933 and Encarsioneura similis Mocsáry, 1909, syn. nov., synonymized by S. ruficornis (Gimmerthal, 1834). S. frigida Mocsáry, 1909, as the synonym of S. sturmii (Klug, 1817) was recovered; Siobla plesia stat. nov. is regarded to be a valid species, rather than a subspecies of S. sturmii. Siobla iridipennis Malaise, 1934 is redescribed based on the holotype, and a new species group, Siobla iridipennis group, is proposed. The characters of the group are briefly discussed. All illustrations of type specimens mentioned in this paper are provided. In addition, the lectotypes of Encarsioneura similis Mocsáry, 1909, Encarsioneura frigida Mocsáry, 1909, and Siobla sturmii plesia Malaise, 1945 are designated here.