Functional carbohydrates are those carbohydrates that have special physiological effects on humans, animals, and plants. Functional oligosaccharides, also known as non-digestible oligosaccharides (NDOs), are diverse groups of simple carbohydrates consisting of monomers present in varying degrees of polymerization ranging between 2 and 10 units. Their molecules have the special structures that are not easily degraded by human digestive enzymes. The main raw materials of functional oligosaccharides are bulk products and wastes in agricultural production, such as starch, bagasse, corncob and whey. As a new physiological active substance, functional oligosaccharides have great potential in nutrition and health care, animal husbandry, plant growth regulation, disease and insect resistance. The development of functional oligosaccharides has become an important industry involving medicine, chemistry, engineering and other disciplines. Functional oligosaccharides are widely used in food, medicine, feed and agriculture. China has made remarkable achievements in the research and development of oligosaccharides. There are more than 100 kinds of oligosaccharide products. Shandong Province plays a leading role in the field of functional oligosaccharides in China and accounts for half of the domestic market share.