Abstract: Based on the second-generation Chinese Academy of Sciences Earth System Model (CAS-ESM2.0), this study firstly introduced a Plant Hydraulics Scheme (PHS) into the land surface component model, CoLM (Common Land Model), to replace the original empirical scheme. Two sets of 34-year (1981~2014) AMIP (Atmospheric Model Intercomparison Project) numerical simulation experiments were then conducted to investigate the impacts of the improved PHS on the simulation of summer precipitation over China. The results demonstrate that the improvement of the plant hydraulics processes significantly reduces the climatological biases of summer precipitation in China by CAS-ESM2.0 model. Notably, it improves the underestimation of precipitation in eastern China and Tibetan Plateau, as well as the overestimation of precipitation in the western Sichuan region. Additionally, it enhances the simulation performance for interannual variability of summer precipitation and the frequency of extreme heavy rainfall days. Further analysis reveals that the improved PHS substantially reduce the model biases in soil moisture, specifically the overly dry bias over the Yangtze River Basin and the wet bias over the Tibetan Plateau. The modifications also reduce biases in simulating surface sensible flux and surface latent heat flux over the Yangtze River Basin, North China, and Tibetan Plateau, thereby improving the model’s representation of land-atmosphere interactions. The improved land-atmosphere coupling significantly enhances the model"s ability to simulate the East Asian monsoon circulation. Specifically, the improved model reduces the negative bias in simulated sea-level pressure over the northwestern Pacific, which favors the intensification of the southwest monsoon and moisture transport from the northwestern Pacific to eastern China. Concurrently, an anticyclonic circulation anomaly can be found in the lower troposphere, which effectively reduces the model biases in the underestimation of weak southerly winds and insufficient moisture convergence over eastern China, leading to a remarkable reduction in precipitation underestimation in eastern China. These findings underscore that an appropriate representation of land-atmosphere interactions, particularly incorporating plant hydraulic processes, is critical for improving simulations of East Asian summer precipitation.