目的：评价美洛西林治疗呼吸道感染的临床疗效。方法：治疗组５４例呼吸道感染患者用美洛西林治疗（Ｉ组），对照组４０例用氨苄西林治疗，剂量３０～６０ｇ，ｂｉｄ，静脉滴注，疗程７～１４ｄ。结果：治疗组和对照组临床总有效率分别为８３３％和６２５％；细菌培养阳性率分别为９２６％和９００％，治疗后细菌转阴率分别为６８０％和４４４％，治疗期间未发现严重不良反应。结论：美洛西林治疗呼吸道感染有较高的临床应用价值。 Objective: To evaluate the clinical efficacy of mezlocillin in the treatment of respiratory tract infections. Methods: 54 patients with respiratory tract infection in the treatment group were treated with mezlocillin (group I), 40 in the control group were treated with ampicillin, and the dose was 3  0 ~ 6  0g, bid, intravenous infusion for 7 to 14 days. Results: The total effective rates of the treatment group and the control group were 833% and 625% respectively. The positive rates of bacterial culture were 926% and 900% respectively. After treatment, the negative rates of bacteria were 680 % And 44  4%, no serious adverse reactions were found during the treatment. Conclusion: The mezlocillin treatment of respiratory tract infection has a higher clinical value.