Abstract: MIL-101(Cr) was modified with trimethylchlorosilane(TMCS) to adjust its hydrophobic properties, and XRD, N₂ adsorption and desorption, FT-IR spectra and surface hydroxyl titration results confirmed that TMCS molecules were grafted via condensation reaction with hydroxyl groups on MIL-101(Cr) surface. Static adsorption capacities of gasoline vapor and water vapor on MIL-101(Cr) and TMCS-MIL-101(Cr) were measured, and the effect of relative humidity on dynamic adsorption of gasoline vapor was also investigated with C₅~C₇ n-alkanes as the model feed. Experimental results show that static adsorption capacities of C₅~C₇ n-alkanes and water vapor on TMCS-MIL-101(Cr) at 25℃ are 0.433 g·g^-1, 0.510 g·g^-1, 0.464 g·g^-1 and 0.233 g·g^-1 respectively. TMCS-functionalized materials show higher C₅~C₇ n-alkanes adsorption efficiency and lower water vapor adsorption efficiency when comparing to MIL-101(Cr). The dynamic adsorption capacities of n-alkanes on TMCS-MIL-101(Cr) at relative humidity 97% were 80% higher than that at relative humidity 0%. Gasoline vapor adsorption performance is significantly enhanced after modification, and water vapor has few effects on gasoline vapor adsorption on TMCS-MIL-101(Cr).