The results of quantum-chemical modeling of possible gas-phase reactions in chemical vapor deposition of Group III-Group V element binary compounds are generalized. Modern computational methods are shown to be capable of obtaining the thermodynamic characteristics of gas-phase reactions in agreement with experimental data. Quantum-chemical methods can be used to estimate the possibility and determine the temperature conditions of formation of oligomeric intermediates during deposition, predict the feasibility of synthesizing new rod-like inorganic polymers, and develop the concept of precursors for the controlled synthesis of III-V composites.