Investigating the constituents of the roots of Vitis thunbergii led to the isolation of four new resveratrol derivatives, vitisinols A-D (1-4), together with (+)-epsilon-viniferin, (-)-viniferal, ampelopsin C, miyabenol A, (+)-vitisin A, and (+)-vitisin C. The structures of these 10 compounds were established by spectroscopic (NMR and MS) analyses. All of the isolated compounds, except 1, were tested for their antiplatelet and antioxidative activities.