Recently,　a　test　model　for　3D　video　coding　extension　of　HEVC　(3D-HEVC)　has　been　drafted.　In　the　model,　a　disparity　vector　(DV)　derived　from　neighbouring　blocks　(NBDV)　is　used　in　the　inter-view　motion　prediction　to　exploit　inter-view　redundancy.　The　accuracy　of　the　derived　DV　affects　prediction　efficiency.　In　the　NBDV　search　process,　however,　the　first　available　DV　among　candidate　DVs　is　chosen.　It　may　not　always　be　accurate.　In　this　paper,　the　NBDV　search　process　is　modified.　Available　DVs　of　each　direction　(temporal,　spatial　left,　spatial　above)　are　checked　based　on　rate　distortion　optimization.　Optimal　DVs　of　three　directions　are　stored　in　a　candidate　list.　When　the　list　is　not　full,　DVs　derived　from　motion　compensation　prediction　are　added　to　the　list.　NBDV　is　finally　derived　by　median　computation　of　candidate　DVs.　The　proposed　method　can　achieve　average　22.9%　encoder　runtimes　reduction　with　a　slight　increase　in　bitrate.