Dandelion is a well-known wild vegetable and traditional medicine herb widely distributed in nature. Extraction, compositional analysis, in vitro antioxidant and antiproliferative activities of dandelion seed oil (DSO) from dandelion seeds (DS) was investigated in this paper. The extraction rate of DSO was 13.46 % using petroleum ether reflux method. 66 compounds and their relative contents were identified by GC-MS. DSO mainly contains olefins, alkanes, alcohols, ketones and other substances, among which (-)-limonene is the most. When the concentration of DSO was 0.24 mg/mL, the W