Abstract:The object was to study the response of plant leaf traits and their related relationships to the thermal environment effect of urban underlying surface and its ecological tradeoff strategy. Results showed that specific leaf area, chlorophyll content, stomatal area, stomatal aperture and leaf nitrogenphosphorus ratio were all increased firstly and then decreased with the increase of environmental surface temperature, which was expressed as grassplanting bricks surface, grass surface, marble surface, cement surface, brick surface, asphalt surface from large to small. While the leaf dry matter content, leaf tissue density, stomatal density, leaf nitrogen content, leaf phosphorus content and leaf vein density showed opposite changes, which were expressed as asphalt surface, brick surface, cement surface, marble surface, grass surface and grassplanting brick surface from large to small. There was a certain correlation between plant leaf functional traits. Specific leaf area showed a significant negative correlation with leaf dry matter content, leaf tissue density and stomatal density (P<0.01), and a significant positive correlation with leaf nitrogen content and leaf phosphorus content (P<0.01). Leaf dry matter content showed a significant positive correlation with leaf tissue density, leaf vein density and leaf nitrogen content (P<0.01). Stomatal density was significantly and negatively correlated with stomatal aperture and stomatal area (P<0.05), and significantly and positively correlated with leaf vein density (P<0.05). Leaf vein density was significantly and positively correlated with leaf nitrogen content (P<0.05) and leaf tissue density (P<0.01). With the increase of surface temperature, the correlation between plant leaf traits was firstly increased and then decreased. The small temperature increase was generally beneficial to strengthen the correlation between leaf functional traits, which significantly reduced its correlation relationship when the temperature was too high. In urban ecosystems, plant leaves showed low specific leaf area, chlorophyll content, stomatal area, stomatal aperture and leaf nitrogenphosphorus ratio, and high leaf dry matter content, leaf tissue density, stomatal density, leaf nitrogen content and leaf phosphorus content. The research further verified the existence of the economics spectrum of the lower temperature of high temperature stress habitat on the underlying surface of the city, and it was a “quick investmentreturn” type in the global leaf economics spectrum, which provided an important theoretical basis for the selection and configuration of urban greening plants and urban planning. The study further validated the existence of economics spectrum in the urban system, which was a “quick investmentbenefit” type.