The　catalytic　oxidation　of　CO　on　Pd-anchored　graphene　oxide　(Pd-GO)　and　Pd-embedded　vacancy　graphene　(Pd-VG)　is　investigated　by　density　functional　theory　calculations.　The　results　validate　both　Pd-GO　and　Pd-VG　show　good　catalytic　performance　for　CO　oxidation.　Meanwhile,　the　more　positive　charge　for　Pd　adatom　and　the　lower　reaction　energy　barrier　make　Pd-VG　system　slightly　superior　than　Pd-GO　system　in　catalytic　performance.　The　reaction　proceeds　via　Langmuir-Hinshelwood　mechanism　with　a　two-step　route　(CO　+　O2　→　OOCO　→　CO2　+　O),　followed　by　the　Eley-Rideal　mechanism　(CO　+　O　→　CO2).　However,　the　synthesis　of　Pd-VG　is　more　difficult　in　experiments　compared　with　the　readily　available　Pd-GO.　Hence,　graphene　oxide　may　serve　as　the　alternative　substrate　to　deposit　Pd　nanoparticles.　©　2014　Springer　Science+Business　Media　Dordrecht.