Oat flour is widely used in beverage after being processed as a kind of grain. In this paper, pasting properties of starch from oat flour were studied using a rapid viscosity analyzer (RVA). Meanwhile, oat gluten was also characterized by measuring ethanol solubility index and the protein properties were determined using dilute lactic acid. The effects of different production processes for oat flour on pasting properties of starch and viscosity characteristics of gluten protein were discussed. We also determined the content of β-glucan in oat flour, which was found to have no obvious effect on the viscosity of gluten protein measured using dilute lactic acid. In addition, the peak viscosity and final viscosity measured using dilute lactic acid had obvious correlations with the final viscosity obtained from the method of ethanol solubility index showing correlation coefficients of 0.810 3 and 0.836 4, respectively, but no correlation with ethanol solubility index was observed.