Starch is an important source of energy for animals,the utilization rate of starch determines the animal, s energy utilization. Starch has a high percentage in diet and low utilization by young animals,and the utilization rate of starch is reduced which leads to energy waste due to the lack of intestinal amylase in young animals. The addition of amylase in the diet can improve the utilization of starch to a certain extent and then improve the production performance in animal. This review summarizes the classification of starch,the structural properties of starch and its effect on the digestion...