High-speed　cutting　(HSC)　is　a　popular　technique　applied　in　manufacturing　as　it　can　significantly　improve　machining　efficiency　and　surface　quality.　However,　when　the　cutting　speed　is　increased　to　extremely　high,　the　deformation　process　of　the　material　will　be　changed　due　to　the　alteration　of　microstructures　and　loading　conditions;　as　a　result,　some　deeper　understandings　of　the　mechanisms　are　still　required.　In　this　study,　a　dislocation　density-based　constitutive　model　is　implemented　to　describe　the　material　behavior　of　OFHC　(oxygen-free　high　conductivity)　copper　during　high-speed　cutting　process,　which　is　then　used　to　obtain　the　characteristics　of　dynamic　stress　propagation　through　physical　parameters　of　the　material,　so　that　the　relationship　between　dynamic　stress　propagation　and　microstructure　evolution　can　be　directly　described.　The　results　show　that　the　propagation　of　plastic　deformation　will　be　significantly　changed　when　cutting　speed　is　increased　to　extremely　high,　and　the　transformation　of　stress　states　between　loading　and　unloading　will　lead　to　the　change　of　gradient　distribution　of　strains　and　microstructures.　This　research　can　be　used　to　understand　the　stress　state　variation　during　dynamic　deformation　in　the　cutting　process　through　microstructure　characterization　in　future　investigations.