To further make karyotaxonomic characterization of Anderson's red-backed vole (Eothenomys andersoni) certain, Ag-NOR-carrying chromosomes were identified by sequential G-band/silver staining in the red-backed voles Myodes (formerly Clethrionomys) rufocanus (Mru), E. andersoni (Ean), and E. smithii (Esm). These voles had the same diploid number (2n = 56), and their karyotypes scarcely differed from each other in chromosome constitution and G-banding pattern. Ag-NORs from these voles were all centromere-cap (cmc) type, being located at the tip of minute short arms of acrocentric chromosomes. Ten pairs of autosomes carried Ag-NORs in Mru, while Ean and Esm carried those on nineteen pairs of autosomes. Ean shared Ag-NORs with Esm on nos. 2, 5, 7, 10, and 13, but not with Mru at all, although nos. 3, 6, 8, 12, 19, 20, 22, 23, and 26 had Ag-NORs in common among three species. These Ag-NORs varied extensively in number from cell to cell with a range of 9–14 in Mru, 14–22 in Ean and 8–22 in Esm. No evidence of Ag-NORs was obtained on the sex chromosomes XY or on nos. 11, 14, and 27 in either species. These findings may be cytological evidence supporting the view of Aimi (1980) who ranked Anderson's red-backed vole as Eothenomys.