The site-specific fragmentation by core-to-valence resonant photoexcitation has been investigated for condensed (CH3S)(2) (dimethyl disulfide). The data presented are the desorption yields of the fragment ions from multilayered (CH3S)(2) around the sulfur K-edge photoexcitation as well as the x-ray absorption and Auger decay spectra. The x-ray absorption spectrum exhibits the double structure of the S 1s-->sigma* resonance peak corresponding to the S 1s-->sigma*(S-S) and S 1s-->sigma*(S-C) photoexcitations. It was found that the S 1s-->sigma*(S-C) excitation is predominantly followed by the CH3+ desorption, but the CH3+ and S+ ions are desorbed in comparable intensity at the S 1s-->sigma*(S-S) excitation. The Auger decay spectra around the S 1s-->sigma* excitation revealed that there exist two kinds of sulfur KL(2,3)L(2,3) spectator Anger decay originating from the S 1s-->sigma*(S-S) and S 1s-->sigma*(S-C) resonant excitations; The observed site-specific fragmentation is interpreted in terms of the localization of the spectator electron in each antibonding orbital, i.e., sigma*(S-S) and sigma*(S-C).