In this book, the structure of an organic compound containing the functional groups such as hydrazone and thiazole was investigated by the experimental and the computational chemistry methods. The compounds containing the hydrazone and the hydrazone are preferred in the industry, the paint industry, the pharmacology, the optics and many fields. Since interest in these compounds has increased recently, our study has been on these compounds. The molecular structure of the C21H20N4O2S compound, illuminated by Xray diffraction method, characterized by IR, 1H NMR and 13C NMR spectroscopic analysis methods, and using DFT and HF methods, which are computational chemistry methods, supported both the experimental studies and the electrostatic potential map, Fukui functions, the nonlinear optical properties and the electronic properties of the molecular structure were investigated. The structure of the molecular structure in both gas and solvent environments was investigated and it was found in which environment it was more stable.