Based on the questions in clinics and pertinent literature, the antibacterial action, half life and adverse reaction of azithromycin and erythromycin were discussed in this paper, and the dosages per day for continuous administration and intermittent administration of azithromycin were calculated. 根据临床中遇到的问题,结合相关文献,应用阿奇霉素半衰期计算其在连续用药和间隔用药中每日体内药量,讨论阿奇霉素和红霉素在临床应用中的抗菌作用、半衰期及不良反应。