[en] Using the method of X-ray diffraction analysis it has been established that, in the subsolidus portion of the system Bi₂WO₆-Bi₂MoO₆-high-temperature stable modification, a wide range of solid solutions from the side of Bi₂WO₆ (up to 60 mol. % Bi₂MoO₆) and a narrow one - de - to 10 mol.% Bi₂WO₆ - from the side of Bi₂MoO₆ exist. Bisub(2)Wsub(1-x)Mosub(x)Osub(6) solid solutions in mixtures of oxides at 550 deg C and sufficient holding time can be formed in all the concentration range. For the solid solution existence regions the concentration dependences of the structural parameters are calculated