Rapeseed oil is one of the most popular types of edible oil worldwide due to its nutrition and flavor properties. The flavor and odor of rapeseed oil depend on the species and amounts of volatile compounds, including aldehydes, alcohols, thiocyanates, isothiocyanates, furans, pyrazines and other heterocyclic compounds. These compounds primarily derived from three pathways during oil processing, including lipid oxidation, glucosinolate degradation and Maillard reaction. In order to improve and modulate the flavor properties of rapeseed oil, it is essential to understand the mechanisms of the three pathways. Lipid oxidation is determined by radical reaction. Glucosinolate degradation can be attributed to enzymatic process or thermal pyrolysis. Maillard reaction is the most important approach but quiet complex. To date, many studies were performed to clarify the formation pathways of flavor compounds. By summarizing the reaction mechanisms, it can be helpful to understand and improve the quality and flavor of rapeseed oil to meet customer's desire.