Abstract: In order to choose the appropriate inactivation method, the effects of different enzyme inactivation treatments, which including hot air roasting, normal-pressure steaming, high-pressure steaming, infrared toasting and microwave heating, on flavor, whiteness, and pasting characteristics of oat flour were studied by electronic nose, sensory evaluation and rapid viscosity analysis. The results showed that PCA fingerprints of electronic nose distinguished different oat flour groups clearly from both two-dimensional and three-dimensional perspective. Sensory evaluation showed that the value of flavor followed the order from high to low: hot air roasting, infrared toasting, high-pressure steaming, normal-pressure steaming, and microwave heating. Whiteness measured by colormeter showed that with microwave treatment was the best, followed by infrared toasting, hot air roasting, high-pressure and normal-pressure steaming, respectively, which was generally in accordance with the results of sensory evaluation. Except pasting temperature, others of six rapid visco-analyser (RVA) characteristics were significantly different from each other. It was concluded that different enzyme inactivation treatments had quite different effects on oat flavor, color and starch gelatinization. According to different use, different inactivation methods should be chosen appropriately.