Abstract: In this paper, the cytological data of Sect. Camellia was collected and summarized, and the disper-sal and differentiation disscussed by means of cytogeographical method. Sect. Camellia contained the same basis chromosome number, x = 15, and varied ploidy, 2x, 4x, 6x and 8x. The 4 species and 2 varieties with glabrous gymoeium, distributed mainly in the south - east and east of China to Japan, were all diploid except some population of C. chekiangcleosa Hu and C. japonica in Korea, but 8 species with hairy gymoeium, dis-tributed concentratedly in Yunnan - Guizhou plateau, included 4 polyploids species or complexes. There were only two kinds of karyotypes, 2A and 2B, in Sect. Camellia. Comparing the asymmitry of the karyotypes showed that karyotype evolution had a clear direction in Sect. Camellia, which was from symmitry to asymmitry. The species in Nanlin mounains and nearby had more - symmitrical karyotype than that far from the above aera. Based on the above results, The authors concluded that Nanlin mount ains and nearby was an original differentia-tion center of Sect. Camellia, and Yunnan- Guizhou plateau was only a second center, where the hybridization and polyoploidization was an important speciation course.

Key words: Sect.Camellia, Ploidy, Karyotype, Cytogeography