In　this　work,　the　experimentally　observed　tribological　phenomena　of　WC-Co　cemented　carbides　were　interpreted　on　the　atomic　scale　using　molecular　dynamics　simulations.　It　was　demonstrated　that　the　friction-induced　deformation　was　mainly　coordinated　by　dislocations　slip　in　both　Co　and　WC　phases,　along　with　the　local　rotation　of　WC　grains　adjacent　to　the　Co　binder.　The　dislocation　motion　within　the　subsurface　Co　phase　was　crucial　for　the　continuous　transfer　of　stress　across　WC/Co　interfaces.　The　fracture　of　WC　grains,　which　frequently　occurs　in　various　friction　processes,　was　found　to　result　from　interactions　between　the　internal　partial　dislocations.　This　caused　formation　of　atomic-scale　micro-voids　early　at　the　intersection.　Significantly　higher　tensile　stress　existed　at　the　WC/WC　grain　boundaries,　which　resulted　in　a　higher　risk　of　intergranular　cracking　compared　to　that　at　the　WC/Co　interfaces　during　the　friction　process.　The　findings　in　the　present　study　facilitate　to　understand　the　tribological　behavior　of　a　variety　of　cermet　materials　hence　to　improve　their　wear　resistance.