The alkaloid extracts of Buxus microphylla Sieb. et Zucc. var. suflyuticosa Makino have yielded eight new alkaloids whose structures and absolute stereochemistry, (Ia-d), (IIa-c), and (III), are described. Apparently, they belong to a new class of triterpene alkaloids and are divided into two series; the first two groups, (I)-(II), possess a fundamental skeleton of the cycloartane type, and the last, (III), one of the cycloeucalane type.