Abstract: A single-side highhydrophobic fluorinated silica/poly(ether sulfone) (fSiO₂/PES) composite membrane was prepared by vacuum-filtrating with tetraethoxysilian (TEOS) and perfluorodecyltriethoxysilane (PFDTES) as the silica source. The chemical component and morphology of the single-side highhydrophobic fSiO₂/PES composite membrane was examined by ATR-FTIR, XPS, TEM and FESEM, individually. The effects of PFDTES modification amount and the heat treatment condition on membrane hydrophobicity were investigated, and the hydrophobic stability of fSiO₂/PES composite membrane was evaluated. The results show that the water contact angle of the single-side highhydrophobic fSiO₂/PES composite membrane is 131.5° when the mass ratio of PFDTES:TEOS is 3. The water contact angle of the single-side highhydrophobic fSiO₂/PES composite membrane is 138.9°, as the heat treatment temperature is 100℃ and the heat treatment time is 4 h. In addition, the single-side highhydrophobic fSiO₂/PES composite membrane exhibits excellent hydrophobic stable performance.