Chlorogenic acid, also known as coffee tannic acid, is a phenolic compound that is a styrene-acrylic substance formed by the plant's shikimic acid pathway during aerobic respiration. Chlorogenic acid is the main active ingredient of traditional Chinese medicine Eucommia ulmoides, which has many pharmacological effects such as choleretic, antibacterial, antiviral, increased white blood cells and excitatory central nervous system. Chlorogenic acid can be purified by an ion exchange resin method.