This paper describes a new method to determine amantadine sulfate in sodium chloride injection by capillary gas chromatography. The chromatographic conditions of the methods employed a SGE BP-1 capillary column (30 m x 0.53 mm i.d., 1.0-microm film thickness); isothermal elution with N2 at a pressure of 100 KPa; injector, oven, and detector temperatures at 220 degrees C, 110 degrees C, and 220 degrees C, respectively; a split-less mode; and a 1-microL injection volume. Naphthalene was used as the internal standard. Peak purity testing with a Varian Saturn 2200 capillary gas chromatography- mass spectrometry system (Varian, Inc.) equipped with a DB-5 capillary column (30 m x 0.25 mm i.d., 0.25-microm film thickness) was performed for the investigation of specificity. There was a linear relationship between peak area ratios of analyte to the internal standard and concentration of analyte over the concentration range 0.1-2.0 mg/mL. The recovery was 97.8 approximately 100.7%. The relative standard deviation (%) of intermediate precision was less than 0.8. The limits of detection and quantitation were 0.2 microg/mL with a signal-to-noise ratio of 3, and 0.7 microg/mL with a signal-to-noise ratio of 10, respectively. The results of determination were similar to the titration method.