The flourishing development of pharmacogenomics, the systematic study of drug metabolizing enzymes and the correlation analysis of genetic polymorphisms have given a new connotation to individualized drug use and brought new opportunities, making today’s clinical individualized drug use more far-reaching. Doctors can make a comprehensive assessment based on individual’s genes, condition, physique, family genetic history and composition of drugs, and can determine the selection of drugs, control of dosage and combination of drugs to achieve accurate and safe use of drugs. The ultimate goal is to improve drug efficacy, avoid drug toxic side effects and reduce blind medical expenses.