1. Their purposes: Compendium of Materia Medica and Tiangong Wu Kai are devoted to the systematic classification and description of nature and human-created objects, so as to promote people's knowledge and understanding of nature and technology.

2. Systematization and classification: both adopt systematic classification. Compendium of Materia Medica is classified and summarized according to the characteristics of plant morphology, taste and function. Wu Kai in Tiangong is classified and arranged according to the characteristics of instrument's use, structure and principle.