The separation and extraction process of protein components in oat were optimized by single factor experiments and the protein subunit components of oat were analyzed by SDS-PAGE. The results showed that the optimal temperature for extraction of oat albumin was 40 ℃, the optimal salt concentration for globulin was 7%, the optimal ethanol concentration for prolamin was 75%, the optimal alkali concentration for glutenin was 0.05 mol/L, the extraction rate of oat protein 83.1%. The results of SDS-PAGE showed that the oat albumin distributed in the range of 10~100 kD; the oat globulin was composed of two subunits with molecular weight in the range of 97.4~100 kD and 43~ 66.2 kD respectively; the distribution range of most oat prolamin subunits was 18.39~40.72 kD; and the distribution range of some oat glutenin subunits was between 20.67~26.66 kD and 43.29~50.80 kD.