The　S-R　(strain-rotation)　decomposition　theorem　has　an　ability　to　capture　strain　components　and　rotation　components　at　the　same　time.　Using　the　principle　of　virtual　power　(VP),　in　this　study,　a　new　formulation　independent　of　specific　numerical　methods　is　proposed　for　the　analysis　of　dynamic　large　or　small　deformation.　Then,　the　formulation　is　applied　to　the　discontinuous　deformation　analysis　(DDA),　yielding　a　new　DDA　based　on　the　S-R　decomposition　theorem,　abbreviated　as　SRDDAvp.　Compared　with　the　conventional　DDA,　SRDDAvp　adopts　a　slightly　modified　basic　variables　together　with　the　generalized-a　method.　The　analysis　of　some　typical　examples　indicates　that　SRDDAvp　can　naturally　overcome　the　issue　of　volume　expansion,　effectively　improve　the　calculation　accuracy　and,　equip　DDA　with　the　potential　to　treat　large　deformation.