摘要： In present work, the ultraviolet absorption spectrum of tetrahydroxy-1,4-quinone hydrate (TH,1,4-QH) has been carried out experimentally (in water, methanol dimethyl sulfoxide, acetonitrile and chloroform) and theoretically in the range 3500-2300 cm-1 in the solution phase. Predicted electronic absorption spectra from time dependent density functional theory (TD-DFT) calculation have been analyzed and compared with the experimental UV-visible spectrum. The effects of hydroxy group substituent in benzoquinone ring have been analyzed. The electronic properties such as excitation energy, wavelength corresponding to absorption maxima (λmax), oscillator strength (f), HOMO and LUMO energies are calculated by time-dependent density functional theory (TD-DFT) using HF/6-311++G(d,p) and B3LYP/6-311++G(d,p) as basis sets. The electric dipole moment (μ), α (polarizability) and β (first hyperpolarizability) have been computed to evaluate the NLO (non-linear optical) response of the investigated compound by Hartree-Fock (HF) and density functional theory (DFT) with B3LYP basis sets. Mulliken atomic charges of the atoms are calculated by DFT (B3LYP). In addition natural bond orbital (NBO) analysis has been done using TD-DFT with B3LYP/6-311++G(d,p) basis sets.