本文介绍用ＨＰＬＣ法同时测定常用的４种苯二氮类药物血清浓度。流动相为甲醇－乙腈－水（４２∶１６∶４２），检测波长为２５４ｎｍ。以氯氮为内标，样品在碱性条件下用叔丁基甲醚提取，氮气吹干后用流动相溶解进样。线性范围为０．０５～３０μｇ·ｍｌ－１，平均回收率为９９．８％～１０１．７％，相对标准偏差为１．２％～７．８％。并用此法对患者血清进行测定。 This article describes the use of HPLC simultaneous determination of the commonly used four benzodiazepines serum concentration. The mobile phase was methanol-acetonitrile-water (42:16:42) and the detection wavelength was 254 nm. To clozapine as an internal standard, the sample was extracted with tert-butyl methyl ether in alkaline conditions, after drying with nitrogen dissolved in the mobile phase injection. The linear range was 0.05 ~ 30μg · ml-1, the average recovery was 99.8% ~ 101.7%, the relative standard deviation was 1.2% ~ 7.8%. And use this method to determine the serum of patients.