Leaf construction cost (LCC), a proxy for the energetic investment plants make to construct leaf biomass, indicates carbon investment strategies of plants across diverse habitats. However, large-scale variations in LCC and their correlations with climate and soil factors have yet been fully explored. To address this knowledge gap, here, we compiled a dataset comprising 442 species-site combinations, spanning nearly all vegetation types in China. We found that LCC exhibited substantial variation, ranging from 0.72 g glucose g⁻¹ to 1.93 g glucose g⁻¹, with an average of 1.25 g glucose g⁻¹. LCC was significantly higher in woody species compared to nonwoody species; however, there was no significant difference in LCC between evergreen and deciduous plants. LCC decreased with increasing latitude and longitude but increased with increasing altitude. Among bivariate LCC-environment relationships, LCC was positively correlated with mean annual precipitation and temperature but negatively correlated with temperature seasonality, precipitation seasonality, soil potassium content, and soil silt content. Collectively, climate and soil factors account for over 54% of the variance in LCC, with soil exerting a more significant influence than climate on LCC. This study offers an exhaustive analysis of the evident pattern of LCC over a large spatial scale, fostering a fresh perspective on functional biogeography and establishing the foundation for exploring the interplay between LCC, ecological functions, and macroevolutionary implications.