The study investigated the effects of trans-ε-viniferin on in vitro maturation (IVM) and gene expression. Three experiments were conducted. Firstly the trans-ε-viniferin was purified from the leaves and stems of the Vitis amurensis , a common wild grape found in Korea, Japan, and China. In the first experiment, a total of 594 cumulus oocytes complexes (COCs) were used for the evaluation of the nuclear maturation. COCs were matured with various concentrations of trans-ε-viniferin (0, 0.1, 0.5, 1.0 and 5.0 μM). After IVM 42 44 h, the nuclear maturation was evaluated. In the second experiment, a total of 300 matured oocytes were used to examine the effects of different trans-ε-viniferin concentrations (0, 0.5 and 5.0 μM) on porcine oocyte intracellular GSH and ROS levels. In the third experiment, the gene expression of oocytes matured with trans-ε-viniferin (0.5 μM) and the untreated group were evaluated after IVM. As results, we observed that trans-ε- viniferin treatment during IVM did not improve the nuclear maturation. But significantly increased (p<0.05) intracellular GSH levels in 0.5 μM group (0 μM vs. 0.5 μM; 14.6 vs. 16.8 pmol/oocyte) and reduced ROS levels (0 μM vs. 0.5 μM and 50 μM; 174.6 vs. 25.7 and 23.8 pixel/oocyte). The trans-ε-viniferin treatment during IVM of recipient oocytes promoted higher (p<0.05) expression of Dnmt1 mRNA in 0.5 μM treatment group than in the control group. But, the other gene expressions (PCNA, OCT4, caspase3, BAK, BAX and sit1) did not significantly differ from the control. In conclusion, these results indicated that the trans-ε-viniferin treatment during porcine IVM increased the cytoplasmic maturation through increasing the intracellular GSH synthesis, reducing ROS levels and increasing the Dnmt1 gene expression.