• Three new flavonoids ( 1 - 3 ) were isolated from the seeds of Psoralea corylifolia for the first time. • Structures of the new compounds ( 1 - 3 ) were elucidated by NMR spectroscopic data. • The relationship between DGAT activity and chemical structure was investigated. • Compounds 1 - 3 , 10 and 11 displayed a high selectivity for inhibitory against DGAT1. Three new flavonoids, including a new prenylated aurone, 7,2′,5′-trihydroxy-8-prenylaurone ( 1 ), and two new flavanones, 2( S )-4′-hydroxy-6-methoxy-7-(2”-hydroxy-3”-methybult-3”-enyl)flavanone ( 2 ) and 2( S )-4′-hydroxy-7-methoxy-6-(1”,2”-epoxy-3”-hydroxy-dimethyl)flavanone ( 3 ), together with eight known flavonoids were isolated from the seeds of Psoralea corylifolia L. The structures were elucidated by detailed spectroscopic analysis and comparison with reported data. Among them, compounds 1 − 3 , 10 and 11 exhibited inhibitory effects on the enzyme activity of DGAT1 in an in vitro assay with IC 50 values ranging from 52.2 ± 1.2–89.2 ± 1.4 μM.