According to chemical structure, non-steroidal anti-inflammatory drug is divided into salicylic acid, propionic acid, acetic acid, fenamic acid and acid type, inhibit cyclooxygenase, block the conversion of arachidonic to prostaglandin, have an effect of antipyretic, analgesic, anti-inflammatory. There is cyclooxygenase-1 and cyclooxygenase-2 in human body. The former mainly exists in the gastrointestinal tract, kidneys, and platelets and so on, if it is inhibited, gastrointestinal injury and other adverse reactions will occur; and the latter is mainly distributed in the inflammatory tissue, involving in the inflammatory process as inducible enzymes.