中文摘要：

通过对中国38个地区共147属,984种兰科植物的区系成分的统计,分析了各地区兰科植物的属种热带成分/温带成分（R/T）值随纬度的变化趋势;并利用SPSS 20.0软件对各地区兰科植物的区系成分进行聚类分析。结果表明：（1）38个地区147属兰科植物可划分为11种分布区类型和9种变型,984种兰科植物可划分为12种分布区类型和6种变型。（2）属级水平上R/T值随纬度的升高总体呈下降趋势,38个地区中23个地区为热带性质,13个地区为温带性质,峨眉山和金佛山的热带性质和温带性质相等;种级水平上除俄贤岭的特殊岛屿石灰岩环境造成极强的热带性质外,其他地区的R/T值随纬度的升高而降低,表现出明显的纬向地带性特点。（3）38个地区兰科植物属种级区系类型存在分异现象,即147属兰科植物以热带亚洲分布（24.71%）、北温带分布（19.14%）和热带亚洲至热带大洋洲分布（15.32%）为主,而984种兰科植物除热带亚洲分布（30.28%）外,则以中国特有分布（26.89%）和中国-日本分布（12.85%）为主。（4）属种级聚类结果显示,种级水平的聚类分析比属级水平的聚类更能体现出纬度相近其区系成分也相近的特点。

英文摘要：

The flora of 984 species, 147 genera of Orchidaceae from 38 regions of China as well as the tend ency of R/T （tropical/temperate character） value with the latitudes were analyzed. All the flora types were clustered with SPSS 20.0. The results revealed that： （1）147 genera can be categorized into 11 types and 9 subtypes,and its 984 species into 12 types and 6 subtypes. （2）At generic level,the R/T values decreased a long with the increase of the latitude in general,and 23 regions are tropical, 13 regions are temperate,and the other two regionsEmei Mountain and Jinfo Mountain,are equal with tropical and temperate character. Whereas,at species level,the R/T values of all other regions just decreased in response to the increase of the latitudes and show a very strong tendency of latitudinal direction zonality, except for Erxianling,where has the most obvious tropical character due to its unique limestone geology. （3）There is a significant differ entiation of the arealtype between genera and species. The Tropical Asia （24. 71%）, North Temperate （19.14%） ,and Tropical Asia to Tropical Australia （15.32%） are the top three arealtypes among all the 147 genera of Orchidaceae in these 38 regions. But in contrast,besides the Tropical Asia （30.28%） ,the rest two main areal types among the 984 species of Orchidaceae are the Endemic to China （26.89%） and the Si noJapan （12.85%）. （4）The cluster analyses indicate that species level is better than the genera level in understanding that the nearer the geographical latitude is, the more similar the flora should have.