The subfamily Helleboroideae (Ranunculaceae) consists of 4 tribes，17 genera and 885 species：Helleboreae (Caltha，12 species，Calathodes，3 species；Trollius，31 species；Megaleranthis，1 species；Beesia，2 species；Helleborus，15 species；Eranthis，8 species)，Cimicifugeae (Soulia，1 species；Anemonopsis，1 species；Cimicifuga，17 species； Actaea，6 species)，Nigelleae (Komaroffia，2 species；Nigella，18 species；Garidella，2 species)，Delphineae (Aconitum，about 400 species；Delphinium，about 320 species；Consolida，46 species)．According to modern distribution of the genera，eight distribution patterns of Helleboroideae are recognized：1)the North temperate distribution pattern：Trollius，
Cimicifuga，Actaea，Aconitum；2)the North temperate plus African distribution pattern： Delphinium；3)The Northern Hemisphere temperate and the Southern Hemisphere temperate disjunct pattern：Caltha；4)the Europe and eastern Asian disjunct pattern：Helleborus； 5)the Western Asian distribution pattern：Komaroffia；6)the Mediterranean distribution pattern：Nigella，Garidella，Consolida；7)the Eurasian and temperate Asian distribution pattern: Eranthis；8)the eastern-Asia endemic pattern：Calathodes，Megalderanthis，Beesia，Souliea，Anemonopsis．The morphological，palynological and cytological characters of the genera of Helleboroideae are analysed．Among them，Calathodes is probably a link between
Caltha and Trollius；Megaleranthis is a link between Calathodes and Trollius；and Beesia is a link between the tribes Helleboreae and Cimicifugeae．On the other hand，statstic data shows that the eastern Asiatic Floristic region (especially Southwest China)is the richest in number of genera，species and endemic species of the Helleboroideae，and there occur many primitive or relatively primitive taxa and most or relatively advanced taxa of this subfamily in that region．To sum up，the eastern Asiatic Floristic region (especially Southwest China) is not only the distribution centre，diversity centre and the centre of endemic groups(certain genera，sections and species)，but also the preservation centre of the primitive taxa and the differentiation centre of the Helleboroideae．