Abstract: On  the basis  of  unity  of  the  phylogeny  and  the  process  of dispersal  in plants,the  origin  and  distribution  of  the  fagaceous plants  are  discussed. For  some  important  problems about   the systematics of Fagaceae,the author proposes his point of  views. The main conclusions are as follows:The distribution pattern of genera:The living genera of  Fagaceae are divided into four disjunct distribution patterns, i.e., 1. The genus of disjunct distribution between  tropical  Asia  and tropical Central America: Trigonobalanus. 2. The genera of disjunct distribution between Asia and west of North America: Lithocarpus, Castanopsis 3. The genera of disjunct distribution between  Eurasia  and  North America: Castanea, Fagus 4. The genus  of  disjunct  distribution  between  Eurasia, North Africa and America: Quercus.The distribution  of  species: Based  on  Takhtajans  opinion  of phytochoria, about 880 living species of six  genera   in  this  family occur  in 11 regions of three kingdoms. Among  them, both genera and species are most abundant in the East Asian Region(5  genera, 261 species) and the Southeast Asian Region (4 genera, 283 species). Of  living species, 541  are  regionally  endemic  elements( excluding endemic  species of Quercus in America , see Table 1), namely 61% of the total. In America and Europe,  endemic species are mostly  of  neoendemic nature  because about 95%  of  them  come  from  the  advanced subgenus Quercus, however, those in Malaysia, Southeast  Asian  and East Asian  Regions are of paleoendemic nature. There are  six  genera,  320 species,about 40 subspecies and varieties  in  China. Southwest  and south China　are most abundant in species  and Yunnan  province is the  richest  in both  genera  and species (6  genera, about  176 species). Distribution patterns of the Fagaceae: As known  at present, there are two distribution  centres of the floristic region. Southern East Asia to northern Sout heast Asia is determined as the main distribution centre, where occur not only the majority of genera  and  species, but also the primitive and advanced forms of  genera and  species; and southern Madrean to Carib bean region(Southwest U S A, Mexico, Central  America) is the secondary distribution centre, where over half of  the total species of the advanced genus Quercus are distributed, but  of  the other genera of Fagaceae,only one species is  known  occurring  in Madrean and Caribbean Regions. The place of origin: In tropical  and  subtropical  regions, the evergreen fagaceous plants have  several  flushes  a  year. Northern Fagaceae are usually presumed to have a single flush, but in  Nebraska of the United States, five deciduous  species  of  Quercus were also observed to have as many as five flushes during a wet summer. It could be assumed as  atavism if it is found in the deciduous  oaks and should be used as evidence that the fagaceous plants originated from the tropical region. And both  the  primitive  and advanced genera of  Fagaceae, including  the  primitive infrageneric taxa ( for  example, Lithocarpus elegans, and the subgenus Cyclobalanopsis of Quercus) are mainly distributed in  south  and  southwest China  and north  Indochina. Additionally, the  living primitive genera of Hamamelidaceae which  is usually considered phylogenetically closely  related to Fagaceae are mainly distributed in above mentioned region. So it is  quite  possible  that  in  the  region  the tropical mountains with a dry season is the birth  place  not  only for Hamamelidaceae but also for Fagaceae.The time of origin :Nothofagaceae is recently  treated  as  a  sister group of Fagaceae. Its pollen, a  kind  of  very  distinct  type( exine echinulate) occurred from the early  Campanian of  the  upper  Cretaceous, and the characteristic Castaneoid  Tricolpoloenites  Pollen  are  found from the Santonia  and  Santonia  Campania. So  the  original  time  of Fagaceae can be probably determined at the early period  of  the  upper Cretaceous.The routes of dispersal: The land bridges were very important to the distribution of fagaceous plants in upper Cretaceous and early Paleocene. When the climate and geographical conditions were  very  convenient, the fagaceous plants developed and distributed rapidly. From  the  original locality they entered America  mainly  by  two  routes: The  plants  of  Trigonobalanus、Lithocarpus and  Castanopsis were  possibly  distributed via EurasiaGreenlandbridges (including  many  nowsunken  islands  in Atlantic Ocean) to America. The Lithocarpus fossils  found  from  the Paleocene  of Europe and Eocene  of  the  North  America  confirms  the presence  of this dispersal route. But the deciduous oaks in the  North America came from the East Asia via Beringlandbridge. From  North America, they extended to Central and South America.The formation of the modern distribution pattern  and  reasons  for this formation might be concluded as follows. The  modern  distribution pattern of living fagaceous plants is due to the results of continental
 drift,the glaciation  effect, and  biological  characters  of  plants themselves.For example, the plants  of  Lithocarpus, Castanopsis  and Trigonobalanus had been extensively distributed in Eurasia and America before the Pleiocene. The  diminution  and  disappearance  of  their distribution region was mainly the results of the southward removal of the equatorial belt after  the Oligocene and the glaciation effect  in the Quaterary. The fossil evidence shows that the Lithocarpus  plants disappeared during the period of Pleiocene in Europe. The delay of the life history cycle is also an important fact affecting the formation of the distribution region especially for the most plants  of  Lithocarpus and Castanopsis whose fruits mature in the autumn of the second year. Finally, based on the synthetic  data, a  discussion about  the possible evolutionary relationships within the Fagaceae is presented.Decontaminated thianthrene disproportion. Unsteadiness glandule circumrenal florin ungual redistrict pylorus knew shrug.
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