The nutritional component of oat groats and the processing quality of oat flake was investigated with 56 portions of oat as samples, and the relationship between them was analyzed. The results showed that a*, amylose content the fat content of oat groats and a*, viscosity and total soluble solid of oat flake were more easily effected by the variety of oat. The fat content and β-glucan content of avena sativa were significantly lower than oat groats（P<0.05）. The water absorption at room temperature and b* of oat flake with husk were significantly higher than oat flake without husk （P<0.05）, while L* was lower（P<0.05）.The color of oat groats had a positive correlation with that of oat flake（P<0.01）. The higher the protein content, amylose content, ash and fiber content of oat groats, the higher the water absorption, total soluble solid and viscosity of oat flake. However, the higher the fat content and starch content of oat groats, the lower the above parameters of oat flake. The protein content of oat groats could significantly influence the water absorption in high temperature and viscosity as well as brewing property of oat flake.