Abstract: Liriodendron chinense×L. tulipifera has been widely used in landscaping and timber forest cultivating because it has many advantages, such as fast growing, high wood qualities, fine form and high ornamental value. In order to know the drought resistance of Liriodendron chinense×L. tulipifera, 8 year old trees in Nanjing City were investigated under the drought situation in summer. The results showed that: Liriodendron chinense×L. tulipifera had strong resistance on the drought. However, the water and chlorophyll content in leaves decreased and the leaves etiolated and defoliated when the trees were in the severe drought stress. If the trees were growing on the Xiashu loess, and the water content in soil was lower than 12%, the leaves of Liriodendron chinense×L. tulipifera would change from green to yellow and defoliate. Therefore, it is necessary to irrigate the trees before the water content in soil decrease to 12% in summer.