Pristine　TiO2/Au　(P-TiO2/Au)　is　modified　by　hydrogen　plasma　(H-TiO2/Au)　or　hydrogen　and　oxygen　plasma　(H-O-TiO2/Au)　treatment,　and　then　used　as　electrochemical　catalysts　for　nitrogen　reduction　reaction　(NRR).　H-TiO2/Au　shows　enhanced　performance　for　the　NRR　process　compared　with　both　P-TiO2/Au　and　H-O-TiO2/Au.　After　hydrogenation　treatment,　some　disordered　regions　on　the　surface　of　TiO2　nanoparticles　are　formed,　and　a　large　number　of　oxygen　vacancies　are　incorporated　into　the　TiO2　crystalline　structures.　When　the　samples　are　used　as　catalysts　for　electrochemical　NRR,　the　yield　of　NH3　of　H-TiO2/Au　is　about　ten　times　compared　to　that　of　P-TiO2/Au　and　about　three　times　that　of　H-O-TiO2/Au,　while　the　highest　Faradaic　efficiency　of　2.7%　is　also　obtained　at　the　potential　of　-0.1　V　for　the　H-TiO2/Au　catalyst.　The　density　functional　theory　(DFT)　calculation　results　confirm　that　H-TiO2/Au　with　oxygen　vacancies　and　the　disordered　surface　layer　is　much　preferred　energetically　for　the　NRR　process.　It　proves　that　enhanced　adsorption　of　N-2　molecules　on　the　catalyst　and　reduced　reaction　barriers　due　to　the　presence　of　defects　play　an　important　role　in　improving　catalysts＇　performances.　The　results　show　that　the　plasma　hydrogenation　technique　can　be　used　as　an　efficient　method　to　modify　catalysts　for　electrochemical　NRR　processes.