Abstract: There are 261 species of vascular plants in the Form.Quercus mongolica that located in the floristic region of NE.China.The temperate florstic elements are 47.47% of the total elements.The E.Asia elements are 42.02%.The endemic floristic elements to China are 10.51%,in which the cospololitan floristic elements are not included.The distribution types of all genera in the Forma.Quercus mongolica are analysed.The temperate distribution types of genera are 90.3%.The florstic elements of the three layer,shrub layer,herbaseous layer and liana are also analysed.

Key words: NE.China, Form.Quercus mongolica, Floristic elements