To investigate the surface microstructures and wettability of different plant leaves, scanning electron microscopy(SEM) was employed to characterize the surface morphologies of four representative plant species: pear, peach, pepper and rice. Meanwhile, the contact angles of four probe liquids-deionized water, formamide, ethylene glycol and N, N-dimethylformamide on both adaxial and abaxial leaf surfaces were measured. Based on these measurements, the surface free energy(SFE) and its components were calculated using the Owens-Wendt-Rabel-Kaelble(OWRK) method. The results showed that the abaxial surfaces of pear, peach, and pepper leaves exhibited distinct elliptical stomata, with pepper leaves showing a significantly higher stomatal density than those of the other three species. In contrast, the adaxial surface of rice leaves displayed pronounced striated structures with uniformly distributed spherical protrusions, whereas the abaxial surface was characterized by striped structures accompanied by numerous symmetrically arranged circular protrusions. Pear, peach and pepper leaves exhibited hydrophilic behavior, while rice leaves were predominantly hydrophobic. For pear, peach, and pepper leaves, the contact angles on the adaxial surfaces were lower than those on the abaxial surfaces, whereas the opposite trend was observed for rice leaves. Consistently, the SFE of the adaxial surfaces of peach leaves was higher than that of its corresponding abaxial surfaces, while rice leaves showed higher SFE on the abaxial surface. Furthermore, the SFE of pear, peach and rice leaves was mainly governed by the dispersive component, suggesting stronger wettability and adhesion toward nonpolar liquid agents. In contrast, the SFE of pepper leaves was dominated by the polar component, indicating that polar solvent-based agents exhibited enhanced wettability and adhesion on pepper leaf surfaces.