Many A3 IIB2 V semiconductors and their solid solutions, that have found a wide practical application in micro- and opto-electronics, have gained much attention and are constantly investigated. We have synthesized and structurally studied, by the single crystal x-ray method, a new α′′′- phase of three-component solid solution with composition (Zn1-xCdx)3As2 , where x=0.26 The monocrystal has been obtained by the modified Bridgman method using the stoichiometric mixture of pure binary Zn3As2 and Cd3As2 components, obtained from pure (99.999 %) Zn, Cd and As. The binary components were subject to purification in vacuum in the vapor phase under the temperature gradient. The x-ray diffraction data were obtained using a single-crystal sample on the Xcalibur Е, CCD difractometer equipped with a monochromatic source of MoKα radiation. The crystal of α′′′- phase is tetragonal, space group I41/amd, a = b = 8.5377(2), c = 24.0666(9) Å. The structure and composition have been refined by the full-matrix least-squares method. Zinc and cadmium atoms were statistically distributed over three symmetry independent positions on mirror planes and tetrahedrally surrounded by four arsenic atoms. The (Zn, Cd) tetrahedrons share common edges and form 3D framework. All A3 IIB2 V compounds are geometrically related with the structure of the defect anti-fluorite structure[1]. In the crystal of α′′′- phase the pseudo-cubic cells of fluorite type have been separated and distribution of tetrahedral vacancies in them has been shown (Figure 1). These vacancies form micro-channels parallel to a and b crystallographic axes, which alternate at different levels of the crystallographic axis c (Figure 2). The structural similarity of α′′phase of Cd3As2[2,3] and α′′′-(Zn1-xCdx)3As2 has been established.