The　optimal　topology　model　is　established　based　on　ICM　(independent　continuous　mapping)　methodology　in　order　to　study　a　topological　optimization　of　continuum　structure　with　displacement　constraints　under　multiple　load　cases.　The　optimal　refers　to　the　structural　mass　as　objective.　And　an　explicit　formulation　of　displacement　that　is　of　global　with　related　to　topological　variables　is　presented　by　using　of　unit　virtual　load　method.　In　addition,　the　dual　model　corresponding　to　the　optimal　model　of　continuum　structure　is　solved　by　the　serial　quadratic　programming.　Consequently,　the　number　of　design　variables　is　decreased　and　the　efficiency　of　computation　is　improved.　Furthermore,　the　present　optimal　model　and　its　algorithm　have　been　implemented　by　means　of　the　MSC/Patran　software　platform　using　PCL　(Patran　command　language).　Numerical　examples　about　2D　and　3D　continuum　structures　indicate　that　the　method　is　effective　and　efficient.