Objective To study the anti-diabetic constituents of the involucre of Castanea mollissima Blume.Methods Compounds were isolated through various chromatography techniques.They were elucidated on the basis of physicochemical and NMR analysis,and their anti-diabetic activity were evaluated by AR inhibitory screening.Results Nine compounds were obtained and identified as kaempferol(1),gallic acid(2),3,4-dihydroxy-benzoic acid(3),ellagic acid(4),Benzyl-O-β-D-glucopyranoside(5),n-butyl gallate(6),2,4,6-trihydroxy-benzoic acid(7),methyl gallate(8),stigmast-4-en-3,6-dione(9),respectively.Conclusions Among them,compounds 57 are isolated from this genus for the first time.Nine compounds show the AR inhibitory activities with different degree,and compounds 4 and 5 exhibit much stronger inhibitory effects than positive control and other compounds.