Abstract: The Detrended Correspondence Analysis (DCA) and Canonical Correspondence Analysis (CCA) have been adopted to detect the relationships among 20 environmental factors,as well as the effects of environmental factors for the plant diversity and geographical components of Genus of 12 areas in Shanxi province.The results reveal that 12 areas may be clustered into 3 types.The first type is mountain areas in the east and west region of Shanxi province,where the elevation is relatively high,and the heterogeneity of habits is strong.The absolute dominant geographical component of genus is North temperate flora.The second type is in the central part plateau and the basin,where the elevation is relatively low,and the conditions intensity of water and temperature is medium,the dominant geographical components of genus is also North temperate flora,but the rate of old world temperate flora and Pan tropic flora is increased.The third type is in the mountain region of south and southeast in Shanxi,where the temperature is relatively high,the dominant geographical components of genus is North temperate flora,but the second dominant components is Trop Asia flora,comparing with the above tow types,the rate of tropic components is increased obviously.

Key words: flora diversity geographic component, distribution pattern, DCA, CCA