A　novel　electrochemical　sensor　for　the　determination　of　formaldehyde　is　introduced　based　on　electrodepositing　nanostructured　platinum-palladium　alloy　in　Nafion　film-coated　glassy　carbon　electrode.　Bimetallic　Pt-Pd　nanoparticles　are　found　to　be　uniformly　dispersed　in　Nafion　film,　as　confirmed　by　scanning　electron　microscopic　analysis.　Energy　dispersed　X-ray　analysis　is　used　to　characterize　the　composition　of　metal　present　in　the　nanoparticle-modified　electrodes.　The　electrocatalytical　behavior　of　the　electrode　is　investigated　by　cyclic　voltammetry　and　linear　sweep　voltammetry.　Experimental　results　show　that　the　electrode　displays　a　remarked　electrocatalytic　activity　for　the　oxidation　of　formaldehyde　and　exhibits　a　linear　relationship　in　the　range　of　10　mu　M　to　1　mM,　with　a　detection　limit　of　3　mu　M　in　acidic　solution.　The　low　detection　limit,　wide　linear　range,　and　high　sensitivity　of　the　sensor　make　it　valuable　for　further　application.