Nine coumarins, osthol, byak-angelicin, ferulin, oxypeucedanin, umbelliferone, umbelliprenin (17), imperatorin, neobyakangelicol and 5-methoxy-8-(2-acetoxy-3-hydroxy-3-methylbutoxy)psoralen [sec-O-acetylbyakangelicin] were isolated. The major component 17 was isolated for the 1st time from the plants growing in Japan.