Abstract: Shenyang city is located in the intersect zone among Changbai，M ongolia and North China flora，which has a plenty of plant species belonging tO 98 families ，371 genera and 779 species ． There are 85 plant species in the
largest fam ily Companulaceae，and more than 20 species in the families Cyperaceae，Rosaceae，Leguminoseae，Polygonuceae,Labiatae．Lilaceae and Ranunculaceae． These families have 384 species in tota1．and 49．3％ of
them are found in Shenyang city．The flora had 23 geographical components types ．and 89．3％ of them were of the temperate type．Based on the epigenesis and functions of vegetation and the role of the dominant species ，the
urban vegetation in the downtown area of Shenyang was divided into 3 vegetation classes，14 vegetation groups and 57 vegetation typ es ，and the components，structure，dynamics and functions of 3 representative vegetation
classes were analysised．