This article makes a contrastive analysis on the first category and second category of traditional Chinese medicine among Chinese Traditional Medicine and Materia Mediea Subject Headings (third edition), the TCMLS Metathesaurus and Chinese Library Classification (fifth edition), and points out the features and defects in these classifications, hoping to give some useful proposals to the construction of traditional Chinese medicine vocabulary. Key words: Traditional Chinese Medicine and Materia Medica Subject Headings; Traditional Chinese medical language system (TCMLS); the TCMLS metathesaurus; Chinese library classification