Abstract: Pomelo,a species of Citrus,has been developed tremendously as a kind of fruit in China in recent decades.There is disagreement with the origin and evolution of pomelo .Here the author gave some comments on the natural differentiation of pomelo and the flux of the centre of genetic diversity, by summing up the studies on the genetic diversity of pomelo and the distribution of almost 70 cultivars in China.The author also pointed out some problems about the research into the biology of pomelo germplasm.

Key words: mixed broadleaved-Korean pine forest, seedling composition, topography, mortality, recruitment.