To reveal the ecological mechanism for various chemical types of Rheum tanguticum Maxim.ex Balf,this paper was designed to investigate the geographical variation of functional components,and further study the critical climate factors and the key period for various components based on the multi-scales climate factors.The methods of Cluster was applied for analyzing the geographical variation of chemical components of R.tanguticum.Coefficient of correlation was used to assess the relationships between the climate factors and the components.Two chemotypes were classified based on the accumulating data,one was the combined anthraquinone chemotype from Qinghai and Gansu province,and the other was the free anthraquinone chemotype from Sichuan province.The relationships between the climate factors and the chemical components were as follows:the anthraquinones were significantly negatively related to annually average temperature.Polyphenols were negatively correlated with annually average temperature and annual preci