Laser Desorption Ionization Time-of-Flight Mass Spectrometry (LDI TOFMS) was used to characterize chalcogenide glasses from pseudobinary (GeSe2)(100-x)(Sb2Se3)(x) system, where x = 5-60, aiming description of their partial structure through the analysis of the plasma formed due to interaction of pulsed laser beam with studied glasses. The plasma contains positively or negatively charged clusters; their stoichiometry was determined as Se-c(-) (c = 2-3), Sb+, Se2+, and Sb-3(+); binary GeSec+, SbSec+/- (c = 1-2), SbbSec+ (b = 2-3, c = 1-4), GeaSb3+ (a = 1-4), Sb2Sec- (c = 3-4), SbSe3-, and Sb3Se5+; ternary GeSbSe2+, GeSbSec- (c = 3-5), GeSbbSe+ (b = 4-5), and Ge9Sb2Sec+ (c = 5-7) ones. Described method is generally useful not only for partial structural characterization of chalcogenide glasses and corresponding thin films but also for evaluation of their contamination with oxygen and/or hydrogen.