Composition and distribution of nitrogen (N) and phosphorus (P) in an organism are interrelated with the environment, and regulates plant nutrition and growth process. In this paper, we review the abiotic, biotic and anthropogenic effects on plant N and P stoichiometry, the influence mechanism of N and P stoichiometry on growth and metabolism of plants, and its effects on the growth, development and metabolite accumulation of medicinal plants. We suggest that N and P stoichiometry could provide new ideas for the research on medicinal plants, including analyzing the growth and metabolism responses of the plants to environmental changes, investigating the interaction between mycorrhizal fungi and the plants, and the identifying limiting nutrient(s). This review could also provide a theoretical basis for scientific planting and resource evaluation of the medicinal plants.