This work aims preparation of polymer-based biocomposite coating by electrostatic spray method onto 316L stainless steel substrate, the present work will compare the effects of incorporation of Al2O3 and TiO2 particles at a different percentage of (10,15 and 20 % wt. from Al2O3 and TiO2 with (90,85 and 80% wt. PMMA - based electrostatic deposition coating is studied. The structure and chemical composition of composite coatings were studied by using (SEM) & (EDS) and mechanical properties (Microhardness and adhesion strength) of Al2O3-TiO2-PMMA composite coating. The SEM&EDX result showed that the composite coating to be dense with uniform dispersants and continuous with a well homogenous mixture within coating exhibits a much-increased Microhardness and remarkably improved adhesion strength.