Barley is one of the major cereal foods for people lived in Eastern Europe, North Africa, Himalayan region in Asia and other region with extreme climate, providing novel functional benefit for human health. The progress in nutritional components and process of barley was summarized in the aspects of starch, fiber, protein and β-glucan. The qualities of barley products were affected by the physicochemical properties of barley and process, which provided information for the development and application of barley food.