In　industrial　practice,　combining　grain　growth　inhibitors　(GGIs)　with　low　carbon　content　effectively　restrains　WC　grain　growth　in　WC-Co　cemented　carbides.　However,　the　intricate　relationship　between　carbon　content,　WC　grain　microstructure,　and　GGI　impact　remains　unresolved.　This　study　investigates　two　WC-Co　sample　sets,　maintaining　constant　VC　inhibitor　levels　but　varying　carbon　content　near　upper　(HC)　and　lower　(LC)　limits.　SEM　analysis　revealed　distinct　morphologies:　HC　displayed　truncated　prism　shapes,　exposing　long　basal　and　prismatic　terraces,　while　LC　exhibited　a　saw-tooth　morphology　with　finer　grains.　EBSD　stereology　quantified　anisotropic　WC　grain　growth,　revealing　suppressed　growth　perpendicular　to　both　basal　(HC:　0.51　mu　m　vs.　LC:　0.38　mu　m)　and　prismatic　planes　(HC:　0.44　mu　m　vs.　LC:　0.37　mu　m)　with　decreased　carbon　content.　Atomic-resolution　EDS　showed　higher　V　solute　excess　in　LC　at　WC(basal)-Co,　WC(prismatic)-Co　interfaces,　and　step　corners　(HC:　4.6,　0.9,　and　4.4　atoms/nm(2);　LC:　5.5,　0.9,　and　7.8　atoms/nm(2)).　Our　findings　elucidate　a　clear　physical　understanding　that　a　low　carbon　content　enhances　V　atom　solubility　within　liquid　cobalt,　increasing　the　thickness　of　complexions　to　quad-layer　on　WC　(basal)-Co　interfaces　and　forming　V-rich　nanoprecipitates　at　step　corners.　Those　inhibitory　effects　further　limited　step　flow,　resulting　in　pronounced　step　bunching　and　a　saw-tooth　fine-grained　morphology　in　LC　sample.　This　study　highlights　that　complexions　housing　more　inhibitory　solute　elements　exert　a　stronger　drag　effect　on　grain　growth　front　migration.　This　approach　has　the　potential　for　studying　grain　growth　in　anisotropic　materials,　highlighting　the　importance　of　constructing　experimental　complexion　diagrams　in　engineering　fine-structured　ceramics　and　metals.