It　is　very　difficult　to　build　a　3D　complex　geological　model　using　conventional　modeling　software.　Based　on　geometric　theories,　the　paper　puts　forward　a　new　method　to　compute　point　cloud　of　a　complex　3D　geological　model　for　a　hillside　landscape　design.　First　according　to　the　model　pattern,　the　model　is　decomposed　into　several　parts,　and　the　point　set　of　each　part　is　calculated　with　the　model　paramaters.　Then　all　the　point　sets　are　gathered　to　form　the　point　cloud　of　the　designed　model,　and　a　surface　is　generated　with　the　point　cloud　using　3D　modeling　software.　Finally　the　surface　is　used　to　incised　the　hillbody　to　obtain　3D　landscape　effect.　By　changing　the　pattern　of　the　design　and　calculating　of　excavated　and　filled　volume,　the　landscape　engineering　can　be　optimized.　©　2014　Taylor　&　Francis　Group.