Abstract: As the main participants in urban greening, garden plants maintain the health and stability of the urban ecological and environmental system. However, the selection mechanism of garden plants often follows past experience or subjective opinions, and always lacks scientific basic theoretical support. As a quantitative indicator of the trade-off of plant resources, leaf economic spectrum reflects the relationship between plant response to changes in the external environment and plant phenotype traits, and could help the researchers choose appropriate plant species when dealing with different environmental factors. Therefore, in order to understand the response of plant leaf economic spectrum traits to water environment, nine typical garden plants in Shihu Scenic Area were taken as the research objects, and the trade-off relationship of their trait variable factors under water environment changes was analyzed from different angles. The results showed that Cinnamomum septentrionale, Nandina domestica, Acer palmatum and Ulmus parvifolia belonged to "quick investment-return" species, while Lagerstroemia indica, Photinia serratifolia, Ginkgo biloba, Osmanthus fragrans and Rhododendron ×pulchrum belonged to "slow investment-return" species. It was concluded that the response of garden plants to water environment changes was different, and it provided an important theoretical guidance for the formulation of the future plant landscape promotion strategies for Shihu Scenic Area.