The　deformation　characteristics　and　plasticity　mechanisms　of　the　WC-Co　composite　were　demonstrated　by　the　molecular　dynamics　simulations　on　the　atomic　scale.　It　was　found　that　the　nucleation,　expansion　and　interaction　of　dislocations　are　distinctly　dependent　on　the　orientation　where　the　load　is　applied.　At　the　same　indentation　depth,　the　dislocation　density　in　WC　is　lower　by　an　order　of　magnitude　than　in　Co.　When　the　indentation　is　applied　on　the　WC　basal　plane,　the　dislocations　form　firstly　on　the　pyramidal　planes　and　are　inclined　to　slip　on　the　prismatic　planes.　At　the　incoherent　WC/Co　interface　in　the　WC-Co　composite,　the　distortion　occurs　with　loading.　In　contrast,　at　the　semi-coherent　WC/Co　interface　containing　dislocation　network,　the　stress　concentration　is　coordinated,　and　the　nucleation　of　dislocations　in　Co　is　triggered.　This　is　favorable　to　enhance　the　resistance　against　intergranular　fracture　of　the　WC-Co　composite.　(C)　2017　Elsevier　Ltd.　All　rights　reserved.