Nanocellulose-stabilized Pickering emulsions have emerged as a promising alternative to conventional surfactant-based emulsions due to their superior stability, biocompatibility, and environmental sustainability. These emulsions have vast potential in food, cosmetics, and pharmaceuticals. Among the key factors influencing their emulsifying performance, the surface charge density of nanocellulose plays a critical role in determining their emulsifying capacity. However, the relationship between surface charge density and the emulsifying capacity of nanocellulose remains unclear, as previous studies often struggle to isolate surface charge density as the sole variable due to confounding factors such as differences in morphology [1, 2].In this study, we systematically investigated the effect of surface charge density on the emulsifying behavior of cellulose nanofibers (CNFs) using both experimental approaches and molecular dynamics (MD) simulations (Figure 1). Two types of CNFs, low-charge CNF (L-CNF) with a surface charge density of 1.3 mmol/g and high-charge CNF (H-CNF) with 2.3 mmol/g, were prepared while maintaining similar morphology to isolate the effect of surface charge. Emulsification experiments were conducted with four organic solvents: chloroform, cyclohexane, n-hexadecane, and 1-octanol.  The experimental findings revealed that L-CNF displayed a greater emulsifying ability than H-CNF, resulting in emulsions with smaller oil droplets. MD simulations offered insights at the molecular level, indicating that CNFs preferentially adhere to the water/oil interface through their hydrophobic surfaces while preserving contact between their hydrophilic surfaces and water molecules. Furthermore, free energy assessments indicated that L-CNF exhibited stronger interfacial adsorption, thereby enhancing van der Waals interactions with the oil phase.These insights will offer valuable insights for designing effective and sustainable CNF-based Pickering emulsifiers for industrial applications.