Here we first time report, the investigation of stable surface (2 mm) oxidized graphite electrode prepared via the anodic oxidation of graphite in different electrolyte medium such as KOH, H2SO4 and KH2PO4. In the electrochemical surface oxidation route, high quality graphene oxide was produced on surface of the graphite rod. The formation of oxidized graphite (Graphene oxide) was proved by X-ray Diffraction (XRD) and Raman spectroscopy analysis. The synthesis product was also characterized by Scanning Electron Microscopy (SEM), etc. The surface oxidized graphite electrode was used for the simultaneous determination of 692 mV catechol and 1.31 V methylparaben. Unbuffered 0.1 M Na2SO4 was used as Supporting Electrolyte (SE), as hydro-alcoholic solution (in 1/4 ethanol/water volume ratio, i.e., 20% volume of ethanol in the final working solution from the cell). The fast and sensitive electrochemical responses for the detection of catechol and methylparaben at a potential between 0 to 1.5 V were obtained. The cyclic voltammetric measurements yielded calibration plots with very superior linearity and high sensitivity Results demonstrated that the electrochemically surface modified graphite electrode displayed a good performance along with high sensitivity and long-term stability.