A pair of new lignan conformers (1-2), one new flavonoid glycoside (3), as well as nineteen known compounds were purified from the twigs and leaves of Cajanus cajan (L.) Millsp.. The planar structures of the unknown compounds were determined via NMR and high-resolution mass spectrometry, while their absolute configurations were elucidated via comparison between their experimental and calculated electronic circular dichroism (ECD) values. All the isolated compounds were assayed for their α-glucosidase inhibitory activities. The results demonstrated that compounds 8-12, 15-16, 18-19, 21-22 had strong inhibition activities, with compound 10 (IC