The effect of chemical substances is reported on the structure, surface morphology, and material properties of vanadium oxide thin films. The study of the chemical substances concentrated on the effects of initial materials (e.g., NH4VO3, NaVO3, VO2, vanadyl acetylacetonate, ammonium decavanadate) and various additives (e.g., acids, chelate ligand, reduction reagent, and tensides). The syntheses are based on sol-gel chemistry. The important aim of the sol-gel technique was to optimize the chemical conditions such as catalyst and solvent for the preparation of perfect V5+-containing layers. The other aim was to check the controllability of the V4+/V5+ ratios. The control was performed in the air by using a reducing agent and in a nitrogen atmosphere. The atomic and bond structures were investigated by 51V MAS NMR, IR, and UV spectroscopies. The supramolecular structures were determined by SEM, EDX, and GIXRD techniques.