Drug plasma half-life refers to a drug into the body, the blood concentration of the drug down to half the concentration of the time experienced is called drug plasma half-life. Each drug has a different half-life, and the frequency of drug administration is determined by the plasma half-life of the drug in order to effectively maintain the blood concentration and achieve the optimal cost-effectiveness of clinical drug administration. Clinical antimicrobial half-life monitoring requirements, but even the same drug half-life is not constant, the influence of many factors, such as the binding rate of plasma albumin, the patient’s physical condition, age, the characteristics of the drug, the impact of disease on the body’s function, as well as the human body’s internal environment, body temperature, acidity and alkalinity and other factors, to be comprehensively assessed.