Abstract: Medicinal plant quality is the basis for ensuring the efficacy of medicinal materials. Here, we investigated the spatial variation characteristics of Angelica sinensis (Oliv.) Diels in Gansu Province, China, based on chemical composition and ecological characteristics. Quality variation patterns in A.sinensis were explored based on the contents of five chemical components as well as climatic factors at different time scales. Results showed that the quality of A. sinensis in Gansu, Yunnan, Sichuan, and Hubei could be divided into high-content (Gansu-Yunnan) and low-content regions (Sichuan-Hubei). Furthermore, ferulic acid, ligustilide, and 3-butylidenephthalide were the three main chemical components causing geographic variation in A.sinensis quality. Mean annual air temperature, ≥10℃ activity accumulated temperature, and average annual relative humidity were the key climatic factors affecting geographic variation in A.sinensis quality. Average monthly air temperature from April to October showed a strong negative correlation with 3-butylidenephthalide and ligustilide content, while average monthly air temperature from May to September showed a strong negative correlation with ferulic acid content. These results suggest that appropriate low-temperature and low-humidity climates are beneficial for ligustilide, ferulic acid, and 3-butylidenephthalide accumulation in A. sinensis, thus explaining the similar quality of A. sinensis in Yunnan and Gansu.