Due to the technological progress and accumulated experience the researcher’s interest to II-VI compounds, in particular to ternary compounds such as Cd1-XZnXTe, and structures based on them has recently increase. This is related to the possibility of using of Cd1-XZnXTe layers as a component of solar cells and ionizing radiation detectors with an integral structure. The variation of the composition parameter x (for x£0,1) leads to the modification of the layer electro-physical parameters. Another procedure in controlling the layers properties is its treatment in CdCl2 solutions. In this paper the information on Cd1-XZnXTe layers fabrication and their electrical and photo-electrical properties as a component part of CdS/ Cd1-XZnXTe structures is brought. Also the information about the investigation of the mechanisms contributing to the enhancement of photo-electrical performances of CdS/Cd1-XZnXTe structures as a result of their treatment in CdCl2 solutions is brought in the paper. Thre investigations were carried out on Cd1-XZnXTe layers and CdS/Cd1-XZnXTe structures fabricated by the evaporation in quasi-closed volumeStructures were fabricated in separate technological cycles in separate reactors. Firstly on a glass substrate, covered with a SnO2 transparent conducting layer, a CdS semiconductin layer was deposited. A following technological stage was the deposition of Cd1-XZnXTe layer. The optimum technological parameters of each fabrication stage were experimentally established. A Ni metallic electrode thermally evaporated in vacuum was deposited on Cd1-XZnXTe layer surface. So in the studied structures SnO2 layer was used as a front electrode and Ni as a bottom electrode. For the estimation of the structures at different technological stages the spectral photo-metrical studies in the wavelength region of (0,5-1,0)μm were carried out on a spectral photometer of UV-1800 (Shimatzu) type controlled by a computer.The substrate,underlayer and layer homogeneity was estimated from their optical transmittancy. The transmittance of the glass/SnO2 substrates and of glass/SnO2/CdS structures is from 8090% and 70-80% accordingly. The transmittancy dependence on the photon energy had shown high values of the ebsorption coefficient in the region close to the fundamental absorption edge. The studies of of CdS/ Cd1-XZnXTe structures photo-conductivity spectral distribution had revealed a narrow conductivity band in the red and partially infrared region of spectra, limited by the wavelengthes from 0,5μm to 0,85 μm. The X-ray structural studies of the structures were carried out on a XTG diffracto-meter by using a radiation of Cu cathode (λKα=1,540Å) by using Bragg-Brentano focusing.The scanning diffraction angles were from 15o to 135o. A continuous scanning of the diffraction patterns was usually carried outby using the recording method of 2qFor the exact determination of the angular positions and the diffraction maxima profiles it was used the step by step scanning mode. In such a way the diffraction pattern of the treated and the untreated in the saturated CdCl2 solution CdS/Cd1-XZnXTe structures were recorded. The diffraction pattern had shown the presence of the Cd1-XZnXTe multi-crystalline phase in the untreated structures having two modifications of the lattice cubic and hexagonal one.The predominant crystallographic direction og a cubical laTTICE IS (111).For the revealing of the hexagonal phase ,which is strongly attenuated by the diffraction patterns superposition specific to the both lattices it was used a q/2q method of diffraction pattern recording. It was qualitatively established that for the specimens, treated at the optimum technological conditions, the contribution of the hexagonal phase is minimum or absent.