Calanthe　fimbriata　is　a　Tujia　ethnic　medicine　with　various　medicinal　value　and　it　is　traditionally　used　for　the　treatment　of　gastric　ulcer,　chronic　hepatitis,　pharyngitis,　and　so　on.The　current　study　was　conducted　to　evaluate　the　antidiabetic　activity　of　C.　fimbriata　methanol　extract　(CfME)　in　oral　glucose　tolerance　test　(OGTT)　mice　and　in　streptozotocin　(STZ)-induced　diabetic　mice.Experimental　diabetes　was　induced　by　intraperitoneal　injection　of　STZ　(60　mg/kg)　for　three　consecutive　days　in　mice.　OGTT　in　mice　and　α-glucosidase　inhibition　assay　were　also　adopted　to　investigate　the　activity　and　elucidate　the　mechanism　of　action.　Gliclazide　and　metformin　were　used　as　standard　drugs　in　OGTT　mice　and　in　STZ-induced　diabetic　mice　experiments,　respectively.　Blood　glucose,　total　cholesterol　(TC),　triglyceride　(TG),　alanine　aminotransferase　(ALT),　aspartate　aminotransferase　(AST),　and　hepatic　glycogen　were　measured　in　plasma　or　in　livers.CfME　exerted　potently　antihyperglycemic　activity　in　OGTT　mice　and　in　STZ-induced　diabetic　mice　and　decreased　ALT,　AST　and　TG　levels,　improved　hepatomegaly,　and　increased　hepatic　glycogen　content,　however,　CfME　failed　to　modify　the　normal　blood　glucose　in　normoglycemic　mice　and　exhibited　weakly　inhibitory　activity　on　intestinal　α-glucosidase.The　present　study　demonstrated　that　CfME　exerted　potently　antidiabetic　activity　by　restoring　the　liver　function　to　increase　the　synthesis　of　hepatic　glycogen　and　by　improving　insulin　resistance　of　peripheral　tissues　to　enhance　the　uptake　and　utilization　of　glucose.