Hypoxanthine,　a　purine　heterocyclic　compound　with　N　and　O　atoms,　has　capability　to　combine　metal　ions　or　adsorb　on　metals.　By　using　density　functional　theory　(DFT)　method　calculation,　the　energy,　charge　distribution,　molecular　orbital　and　vibration　spectra　information　of　tautomeric　hypoxanthine　were　given.　Combined　with　these　DFT　results,　the　influence　of　pH　on　the　structure　of　tautomeric　hypoxanthine　was　studied　by　surface　enhanced　Raman　spectroscopy　(SERS).　Electrochemical　SERS　was　applied　to　study　the　properties　of　hypoxanthine/gold　interface.　It　is　found　that　the　structure　of　adsorbed　hypoxanthine　was　changed　from　slightly　tilted　to　upright　with　negatively　moving　of　potentials.　©　2015　Elsevier　Ltd.