A　systematic　modeling　study　is　conducted　to　predict　the　dynamic　response　of　magnetorheological　(MR)　damper　based　on　a　refined　constitutive　model　for　MR　fluids.　A　particle-level　simulation　method　is　first　employed　to　probe　the　microstructured　behavior　and　rheological　properties　of　MR　fluids,　based　on　which　the　refined　constitutive　model　is　developed.　The　constitutive　model　is　further　validated　by　comparing　the　predicted　results　with　the　data　obtained　from　microscopic　simulations　and　existing　experiments.　It　is　revealed　that　the　proposed　constitutive　model　has　comparable　accuracy　and　good　applicability　in　representing　MR　fluids.　Subsequently,　a　computational　fluid　dynamics　(CFD)　model　is　established　to　explore　MR　damper＇s　behavior　by　using　the　proposed　constitutive　model　to　describe　the　fluid　rheology.　For　better　capturing　the　dynamic　hysteretic　behavior　of　MR　damper,　a　modified　parametric　model　is　developed　by　combing　the　Bingham　plastic　model　and　the　proposed　constitutive　model.　The　modified　model　for　MR　damper　shows　its　validity　and　superiority　over　the　existing　Bingham　plastic　models.