Abstract: The rare and threatened plants are the most precious wealth to mankind.Henan Province situates in the Central Plains of China.Alot of such plants in it were preserved due to its plentiful water and heat resources and its various topography.In order to start a new way to study the genetic properties and the biodiversity of the plants,this paper, through evaluating the ornamental characteristics of their flowers, fruits,leaves,shapes, etc., tries to combine the protecting and saving work with the afforestating, beautifying, and purifying construction of cities and towns.According to the present situation of the rare and threatened plants in Henan which have been used in gardens and their further appliance to cities and towns, some suggestions have been made at the end of the paper for reference.