Results of the experimental and theoretical investigation of X-ray absorption S K near-edge structure in complex compounds containing a sulfurcarbon double bond mostly in the thioureato group are presented. In the framework of a quasi-atomic model the splitting of the 1s^-13p resonance of the sulfur atom has been found to dominate the S K XANES. The splitting of this resonance into three (one π* and two σ*) components allows to explain the main features in the spectral density of oscillator strengths of transitions from the S K-shell. To describe the splitting both the resonance effects inside the SCN₂ group and the influence of atoms located in opposition to the sulfur atom have to be taken into account. Applying the quasi-atomic approximation the variation of the partial charge on the sulfur atom in the compounds is analyzed.