in the CuSe (1 - x)CrSe xVSe system, CuCr1 - xVSe2 solid solutions isostructural with CuCrSe2, CuCr2Se4 spinel and Cu3VSe4 were found. For CuCr(1 - x)VxSe(2) solid solutions, the replacement of Cr by V up to x = 0.25 was established. Oxidation states of Cr and V were determined from paramagnetic susceptibility measurements. The CuCr1 - x VxSe2 solid solutions were found to be electronic and Cu+-cationic mixed conductors. The unit cell sizes were shown to play an important role in determining the Cu+-cationic conductivity compared with chemical bond character.