By Investigating the variation patterns of functional traits in Salix matsudana and Haloxylon ammodendron leaves across different growth stages in the Yellow River Ulan Buhe Desert region, this study explore how these species adapt to the unique environmental conditions of the area. Salix matsudana and Haloxylon ammodendron in the Ulan Buhe Desert section of the Yellow River were selected as research subjects, with 14 leaf functional traits measured across three growth stages: early (early May), peak (early July), and late (early September). The variation and correlation of leaf functional traits at different growth stages, as well as their response to meteorological factors, were analyzed. The results showed that: (1) Leaf functional traits of both species exhibited varying degrees of variation across different growth stages. Among them, the coefficient of variation of leaf dry weight of Haloxylon ammodendron and relative water deficit of Salix matsudana were the highest, at 91.78% and 45.74%, respectively. The coefficient of variation of leaf carbon stable isotope ratio (δ¹³C) of both plants was the smallest (both less than 5%); There were significant differences (P<0.05) in the water content, leaf width, and leaf shape index of dry willow leaves, as well as in the water content, specific leaf area, and specific leaf weight of Haloxylon ammodendron during the early, vigorous, and late stages of growth.(2) The correlation between functional traits of Haloxylon ammodendron leaves exceeds that in Salix matsudana leaves; Leaf length and δ¹³C consistently emerge as key indicators, ranking among the top three comprehensive functional traits of two plant leaves.(3) Meteorological factors explained 23.89% of the variation in leaf functional traits of Salix matsudana and Haloxylon ammodendron, with specific humidity (QV) and precipitation (PCP) being the main meteorological factors affecting leaf functional traits of Salix matsudana and Haloxylon ammodendron, respectively; QV and total effective radiation on clear sky surfaces (PAR) are meteorological factors that jointly affect leaf functional traits of two plant species. Plants adapt to complex environmental changes by modifying leaf functional traits and balancing trait relationships, thus optimizing survival strategies through adjustments in resource acquisition and material allocation.