Abstract: This invention involves a plasma treated and controllable release antimicrobial peptide coated titanium alloy for surgical implantation, where the alloy with antimicrobial properties is fabricated using surface techniques without adversely compromising its biocompatibility and original mechanical properties. The surface techniques form antimicrobial layers on the alloy capable of resisting microbial adhesion and proliferation, while allowing mammalian cell adhesion and proliferation when the alloy is implanted to human body. In one embodiment, PIII&D is applied to incorporate ions, electrons, free radicals, atoms or molecules on a titanium alloy substrate. A pressurized hydrothermal treatment can be carried out to establish reactive functional groups for antimicrobial purpose or for connecting the substrate and external antimicrobial molecules.