Abstract: More than 20 species of the genus Caragana distributed mainly from Qinling mountain and northward and their 59 morphological characters were analyzed. Both phonogram and cladogram revealed that the taxa with pinnate or palmate leaves were grouped into clusters of their own. The cladogram showed that C. arborescens and its related taxa, C. stipitata ect. were primi-tive. Along the distributed region of C. arborescens, the genus radiated adaptively westward and southwestward into ecological series resulted from factors of temperature and precipitation, that is, I. forest species→forest→steppe species→steppe species→ desert species; forest species→ alpine montane species, II. humid zone→semihumid zone→semidrought zone→drought zone.

Key words: Caragana