ObjectiveTo use high-performance liquid chromatography-time of flight mass spectrometry (HPLC-TOF/MS) for analyzing the chemical constituents of Fuzhengpingxiao Capsule. MethodsThe separation was performed on a Agilent Eclipse plus C18 reverse phase column (4.6 mm×250 mm, 5 μm)．The mobile phase consisted of water containing 0.1% formic acid and acetonitrile was used as gradient elute．The flow rate was 1 ml/min, the post-column split ratio was 31, and the temperature of column was 25℃. Time-of-flight mass spectrometer(TOF/MS) and electrospray ion source (ESI) was employed for qualitative analysis under both positive and negative ion mode, and mass scan range was m/z 100-1 100. ResultsA total of 247 major chemical constituents were identified in Fuzhengpingxiao Capsule by HPLC-TOF/MS, including 168 in positive mode, 103 in negative mode, and 24 in both. The source herb of the components were identified. ConclusionAn efficient HPLC-TOF/MS approach has been established for studying the chemical constituents in Fuzhengpingxiao Capsule, which paves a way for the quality control and further in vivo studies of the preparation.