To　satisfy　the　popularity　of　3D　application,　3D-HEVC　has　been　developed　as　a　new　video　encoding　standard　for　multiviews.　What＇s　more,　as　the　development　of　internet　and　mobile　services,　the　use　of　3D　video　application　from　the　big　screen　to　mobile　devices　become　an　inevitable　trend.　So　an　efficient　transcoding　for　3D　videos　is　necessary.　In　3D-HEVC,　3D　video　is　comprised　by　multiview　video　and　corresponding　depth　maps.　The　computational　complexity　is　further　increased　caused　by　depth　maps.　In　order　to　reduce　the　computational　complexity　caused　by　the　mode　decision　for　depth　maps,　an　efficient　fast　intra　mode　decision　for　3D-HEVC　depth　maps　down-sizing　video　transcoding　based　on　SVM　(support　vector　machines,　SVM)　is　proposed　in　this　paper.　Compared　with　the　HTM16.0　which　employs　the　original　intra　mode　decision,　the　proposed　algorithm　can　save　about　16%　of　transcoding　time　without　distortion　of　synthesized　intermediate　views.