This　paper　analyzes　the　relationship　between　macroblock　(MB)　modes　and　depth　values　in　multiview　video　plus　depth　(MVD)　format,　and　proposed　a　depth　based　mode　decision　algorithm　for　3D　video　coding.　The　depth　information　was　utilized　to　determine　the　final　mode　decision　process.　The　experimental　results　show　the　proposed　algorithm　can　reduce　the　complexity　of　the　mode　decision　process　remarkably　while　maintaining　nearly　the　same　rate　distortion　performance.