This method outlines the technical requirements for the qualitative screening and quantitative determination of 23 ingredients in cosmetics by means of high performance liquid chromatography-tandem mass spectrometry. It is applicable to aqueous liquids, creams, emulsions, gels, oil-based liquids, and powder cosmetics. Compared with the existing method in Safety and Technical Standards for Cosmetics, this new method expands the scope of ingredients tested from 7 to 23, and has been optimized to also apply to powder formulations.