The　average　interface　area　aspect　ratios　of　carbide　grains　in　WC-Co　composites　are　measured　from　basal-to-prismatic　area　ratios　determined　by　the　five　parameter　analysis　(FPA　method.　Grain　boundary　plane　distributions　regardless　of　misorientations　indicate　that　the　(0001)　basal　and　(10　(1)　over　bar0)　prismatic　planes　are　the　most　common　habit　planes,　and　the　interface　area　aspect　ratio　is　determined　by　the　ratio　of　the　(0001)　plane　area　to　the　(10　(1)　over　bar0)　plane　area.　Additionally,　the　measured　aspect　ratios　are　found　to　vary　with　the　densification　mechanisms　of　the　WC-Co　composites.　The　work　offers　a　new　alternative　to　characterize　the　geometry　of　carbide　grains　in　WC-Co　composites.　(C)　2014　Elsevier　Ltd.　All　rights　reserved.