Automatic　and　objective　body　condition　scoring　of　dairy　cow　has　aroused　great　researches　as　a　method　to　assist　management　of　nutritional　programs　in　dairy　herds.　This　study　presents　a　3-dimensional　surface　fitting　approach　that　provides　a　structure　description　of　dairy　cow＇s　body　for　BCS　estimation.　a　3-dimensional　algorithm　that　provides　a　topographical　understanding　of　the　cow＇s　body　to　estimate　BCS.　In　this　study,　the　hypothesis　tested　was　that　the　body　contour　of　a　fatter　dairy　cow　is　plumper　than　that　of　a　thin　dairy　cow　and,　therefore,　may　better　fit　a　paraboloid　surface.　Depth　image　processing　and　fitting　model　were　investigated　and　consisted　of　three　stages:　(1)　object　location　and　separation　of　individual　cow;　(2)　image　surface　fitting;　and　(3)　parameters　determination　in　body　condition　scoring　(BCS)　model.　Compared　with　the　previous　studies,　the　novelty　in　this　paper　was　completing　the　full-automation　of　a　BCS　system.　The　proposed　model　was　trained　and　tested　with　the　BCS　value　obtained　manually.　Pearson　correlation　between　the　proposed　BCS　and　the　manual　BCS　was　0.84　for　the　test　data　set.　©　2019　IEEE.