Radix peucedani is a traditional Chinese medicine mainly used to facilitate expectoration and suppression of cough. In this study, high-performance liquid chromatography (HPLC) was used to analyze 20 radix peucedani samples. The plants were classified as wild or cultivated, and flowering or non-flowering. The level of each ingredient was determined by peak area normalization, and the effects of cultivation and flowering on the levels of 14 ingredients were evaluated through an independent-sample t-test. The data revealed that flowering radix peucedani had significantly lower levels of (±)-praeruptorin A (Pd-Ia), praeruptorin C (Pd-C), and (+)-praeruptorin D (Pd-D) compared with those from the non-flowering ones (P < 0.05), whereas cultivated radix peucedani had lower levels of Pd-Ia, (±)-praeruptorin B (Pd-II), Pd-C, and Pd-D compared with those from wild ones (P < 0.05). The influence of each ingredient, cultivation, and flowering on the expectorant effects of radix peucedani was investigated in mice using phenolsulfonphthalein (phenol red) excretion test. The results showed that Pd-Ia, Pd-III, and Pd-D are the major active ingredients responsible for the expectorant effects of radix peucedani. Compared with the samples from non-flowering plants, those from flowering radix peucedani exhibited a remarkably reduced capability to promote phenolsulfonphthalein excretion in mice (P < 0.05); similarly, cultivated radix peucedani had reduced efficacy compared with the samples from wild plants (P < 0.05). Therefore, cultivation and flowering have significant effects on the active ingredient content and the expectorant effects of radix peucedani. Key words: Radix peucedani, cultivation, flowering, ingredients, facilitating expectoration.