In this book, chemical studies are described mainly from literature reports appearing since 2000, inclusive of investigations performed by the present authors, on the diversity in secondary metabolites ofLigulariagrowing in the Hengduan Mountains area of China, focusing on eremophilane sesquiterpenoids and other metabolites. More than 100Ligulariaspecies and their related genera in the plant family Senecioneae plants (Cremanthodium, Cacalia, Senecio, and others) grow in East Asia. For many years, researchers have studied the chemical constituents of these plants, and terpenoids, flavonoids, steroids, alkaloids, and aromatic compounds have been isolated. Among these, in particular, numerous sesquiterpenoids were reported. Within this book terpenoids and aromatic compounds (total 1049), both previously unknown and known, are presented. Finally, genetic studies and synthesis investigations are briefly reviewed.