Carbon　support　is　essential　for　electrocatalysis,　but　limitations　remain,　as　carbon　corrosion　can　lead　to　electrocatalyst　degradation　and　affect　the　long-term　durability　of　electrocatalysts.　Here,　we　studied　the　corrosion　dynamics　of　carbon　nanotubes　(CNTs)　and　Vulcan　carbon　(VC)　together　with　platinum　(Pt)　nanoparticles　in　real　time　by　liquid　cell　(LC)　transmission　electron　microscopy　(TEM).　The　results　showed　that　CNTs　with　a　high　degree　of　graphitization　exhibited　higher　corrosion　resistance　compared　to　VC.　Furthermore,　we　observed　that　the　main　degradation　path　of　Pt　nanoparticles　in　Pt/CNTs　was　ripening,　while　in　Pt/VC,　it　was　aggregation　and　coalescence,　which　was　dominated　by　the　interactions　between　Pt　nanoparticles　and　different　hybridization　of　carbon　supports.　Finally,　we　performed　an　ex　situ　CV　stability　test　to　confirm　the　conclusions　obtained　from　in　situ　experiments.　This　work　provides　deep　insights　into　the　corrosion　mechanism　of　carbon-supported　electrocatalysts　to　optimize　the　design　of　electrocatalysts　with　a　higher　durability.