A novel gold complex: [Au(5 5´-dmbipy)(Cl)2] (a) which dmbipy is 5 5́-Dimethyl-2 2́-bipyridine has been synthesized and different techniques were applied to confirm the chemical structure. The structure consists of a gold cation chelated by one neutral bipyridine ligand two (Cl-) ions and one (Cl-) ion inside and outside of the coordination sphere respectively.Thermodynamic parameters (ΔH° ΔS° and ΔG°) calculated from FS-DNA interaction of complex showed that electrostatic binding have an essential function in the interaction of DNA–Au(III) complex.Additionally relative viscosity of DNA did not change while the concentration increased. As proved by Circular dichroism (CD) spectra the DNA structure changed.Interestingly the synthesized compound exhibited an effective cytotoxic behavior against cancerous cell lines. The molecular docking exploration indicated the non-intercalative mode of binding which confirms the obtained results from spectroscopy viscometry and CD techniques.