The anti-oxidative activity of ethanol and methanol extracts from various seed oils (perilla seed oil, camellia seed oil, pine seed oil, flaxseed oil, and olive oil) was investigated using DPPH free radical scavenging activity (DPPH-RSA), hydroxyl radical scavenging activity (Hydroxyl-RSA), fluorescent development, browning level development, microsomal lipid peroxidation (MLP), and t-BOOH-induced cytotoxicity assays. Both browning and fluorescence level were observed higher value in methanol extract of camellia seed oil (CSO-ME). This meant that CSO-ME had more available antioxidant matters. Radical scavenging activity of CSO-ME was the highest among all seed oil extracts, and was 61.1% in the DPPH-RSA and 64.5% in the Hydroxyl-RSA test. Based on in vitro tests, all extract treatments significantly reduced both thiobarbituric acid-reactive substrate formation and lactate dehydrogenase release, indicating high antioxidant activity. These results suggest that ethanol and methanol extracts from seed oils can be a potentially good dietary lipid supplement source against oxidative stress.