Pd　nanoparticles(NPs)　electrodeposited　onto　indium　tin　oxide(ITO)　surface　were　applied　to　the　study　of　the　electrocatalytic　activity　of　ethanol.　Firstly,　cyclic　voltammetry　and　chronoamperometry　were　employed　to　study　the　deposition　mechanism　at　the　initial　stage　of　Pd　electrodeposition　on　ITO.　The　deposition　process　was　irreversible　which　was　controlled　by　the　diffusion　of　[PdCl　4]　2-,　and　the　diffusion　coefficient　of[PdCl　4]　2-　was　calculated　to　be　2.19×10　-5　cm　2/s.　Comparing　the　current　transient　data　at　different　potentials　with　those　predicted　by　the　instantaneous　and　progressive　nucleation　models　under　diffusion　control,　progressive　three-dimensional　nucleation　mechanism　was　proposed　for　the　nucleation　of　Pd　on　ITO　at　-0.1　V.　The　mechanism　changed　to　the　instantaneous　nucleation　mode　at　-0.3　V.　FESEM　images　of　the　electrodeposits　show　that　the　size　of　Pd　NPs　is　affected　by　the　deposition　potential　and　the　deposition　period.　Secondly,　the　structure　of　Pd　NPs　was　analyzed　with　XRD　and　the　electrochemical　behavior　on　ITO　was　studied　in　the　solution　of　0.5　mol/L　H　2SO　4,　respectively.　Finally,　the　obtained　Pd　NPs/ITO　were　applied　in　the　electrocatalysis　of　1.0　mol/L　ethanol　in　alkaline　solution,　which　displayed　superior　electrocatalytic　activity.