Previously, a methanol extract from seeds of Paeonia lactiflora was shown to have a potent inhibitory activities against tyrosinase and soybean lipoxygenase (SLO). Seven stilbenes, trans-resveratrol-4-O-β-D-glucoside, transresveratrol, trans- ε-viniferin, cis- ε-viniferin, gnetin H, suffruticosol A and B were isolated from the seeds as active principles for inhibition of the enzymatic activity. Among them, the resveratrol trimer, gnetin H exhibited the most potent inhibitory activities against tyrosinase and SLO, respectively. Additionally, the resveratrol dimers, trans- ε-viniferin and cis- ε-viniferin exhibited significant inhibitory activity against the two oxidative enzymes. Meanwhile, three other stilbene derivatives, such as trans-resveratrol, suffruticosol A and suffruticosol B had also weak inhibition activity. The least inhibitory activity was observed in transresveratrol- 4-O-β-D-glucoside. These results suggest that resveratrol dimers and trimer in the seeds of Paeonia lactiflora are potentially useful therapeutic agents against pathological disorders such as hyperpigmentation and inflammation.