Spatial　Clustering　with　Obstacles　Constraints　(SCOC)　has　been　a　new　topic　in　Spatial　Data　Mining　(SDM).　Spatial　Obstructed　Distance　(SOD)　is　the　key　to　SCOC.　The　obstacles　constraint　is　generally　ignored　in　computing　distance　between　two　points,　and　it　leads　to　the　clustering　result　which　is　of　no　value,　so　obstructed　distance　has　a　great　effect　upon　clustering　result.　In　this　paper,　we　propose　a　novel　Spatial　Obstructed　Distance　using　Dynamic　Piecewise　Linear　Chaotic　Map　and　Dynamic　Nonlinear　Particle　Swarm　Optimization　(PNPSO)　based　on　Grid　model　to　obtain　obstructed　distance,　which　is　named　PNPGSOD,　it　is　not　only　simple　and　easy　to　actualize,　but　also　convergent　rapidly,　the　experimental　results　are　provided　to　verify　the　effectiveness　and　practicability.　©　2010　Springer-Verlag.