The objective of this study was to investigate to influence of glutathione (GSH) on development and antioxidant enzyme activity in tetraploid porcine embryos. Tetraploid embryos were produced using parthenogenetic 2-cell embryo by electrofusion method. Tetraploid embryo development was observed every 24 hours and intracellular antioxidant enzyme activity was measured at 120 hours after electrofusion. The 4-cell to 16-cell stage tetraploid embryos was increased in 100 and 500 μM GSH-treated groups compared control group at 48 hours (P < 0.05) but cleavage rates were not significantly different among the GSH treatment groups at 48, 72, 96, and 120 hours. Blastocyst formation was significantly increased by 300 and 500 μM GSH at 120 hours in tetraploid embryos (P < 0.05). But blastocyst cell number were not significantly different among the GSH treatment groups (16.4 ± 0.8, 16.8 ± 2.6, 18.5 ± 2.8 and 17.5 ± 1.8). The intracellular antioxidant enzyme level was increased in 500 μM GSH compared to 0 and 100 μM GSH (P < 0.05). We suggest that GSH may be improve development of tetraploid embryo in pigs.