目的　研究仙人掌的化学成分。方法　采用硅胶柱色谱法、离子交换色谱法分离仙人掌化学成分 ,用波谱学方法鉴定结构。结果　自仙人掌中分得 3个化合物 ,分别鉴定为仙人掌素B(I)、羟脯氨酸 (II)、酪氨酸 (III)。结论　I为新化合物 Objective To study the chemical composition of cactus. Methods The chemical components of cactus were separated by silica gel column chromatography and ion exchange chromatography. The structures were identified by spectroscopic methods. Results Three compounds were isolated from cactus and identified as cactin B (I), hydroxyproline (II) and tyrosine (III). Conclusion I is a new compound