Abstract:Magnoliaceae is a widespread family in tropical, subtropical and warm-temperate regions, especially in East and Southeast Asia, southeast of North America,Central America and the north part of South America.There are 15 genera and about 246 species in the world, 11 genera and 99 species in China. East and Southeast Asia is the centre of recent distribution of Magnoliaceae.According to the evolutionary tendency of the characters and the geographical distribution of this family, we propose a new system by dividing it into two subfamilies, Magnolioideae and Liriodendroideae Law;wo tribes,Magnolieae and Michelieae Law, five subtribes,Manglietiinae Law, Magnoliinae,Alciman driinae Law,Elmerrillinae Law,Micheliinae; and fifteen genera.Based on the evidence of fossil records and modern distribution of Magnoliaceae,it is reasonable to presume that this family1was possibly originated from southwest region of China in very early Cretaceous and radiated from there, and its dispersal routes might be 1. from Southwest China through Japan, Far East of Russia, Bering land bridge, to North America;2.From Southwest China through Old Qinling mountain area,West Siberia, Europe, Greenland, to North America, and then to South America;3.From South China through Indo-China,Malay Peninsula, to New Guinea. The formation of disjunct distribution between East Asia and North America was due to the glaciation during the late Tertiary and Quaternary Periods. Most magnoliaceous plants were extinguished in Europe and the west of North America, with the exception of some plant refuges. The Magnoliaceae in South America was distributed from NOrth America about in Miocene.
