WETTABILITY AND REPELLENCY ARE IMPORTANT PROPERTIES OF SOLID SURFACE FROM BOTH FUNDAMENTAL AND PRACTICAL ASPECTS. RECENTLY, SYNTHESIS OF HYDROPHOBIC SURFACE HAS RECEIVED A GREAT ATTENTION [1]. IN THIS RESEARCH, WE STUDIED A SIMPLE DIP COATING METHOD FOR THE PREPARATION OF THERMALLY STABLE, TRANSPARENT HYDROPHOBIC SILICA FILM ON THE GLASS SUBSTRATE AT ROOM TEMPERATURE USING ISOOCTYLTRIMETHOXYSILANE (ISO-OTMS) AS A SILYLATING AGENT BY THE SOL-GEL PROCESS. THE EFFECT OF HYDROPHOBIC AGENT ON THE SURFACE STRUCTURE AND HYDROPHOBICITY HAS BEEN RESEARCHED. THE STATIC CONTACT ANGLE VALUES OF THE SILICA FILMS INCREASED FROM 66° TO 140°. THE SILICA FILMS HAVE BEEN CHARACTERIZED BY ATOMIC FORCE MICROSCOPY (AFM), FOURIER TRANSFORM INFRARED SPECTROSCOPY (FTIR), CONTACT ANGLE MEASUREMENT (CA), THERMAL STABILITY BY TG-DTA ANALYSIS, PERCENTAGE OF OPTICAL TRANSMISSION AND FIELD EMISSION SCANNING ELECTRON MICROSCOPY (FE-SEM) IMAGES. THE FIELD EMISSION SCANNING ELECTRON MICROSCOPY IMAGES OF THE HYDROPHOBIC SILICA FILM, BEFORE AND AFTER MODIFICATION REVEALED THAT THE PARTICLE SIZE OF SILICA IS 40 NM AND 70 NM, RESPECTIVELY. THE IR SPECTRA CONFIRMED THE MODIFICATION OF THE SILICA NANOPARTICLES BY DISPLACING THE POLAR AND HYDROPHILIC GROUPS’ ─OH WITH NONPOLAR BONDS LIKE SI─C AND C─H LEAD TO INCREASE IN THE HYDROPHOBICITY OF THE SILICA FILM [2]. AFM IMAGES SUGGEST THAT THE SURFACE ROUGHNESS VALUE, CONTRIBUTES TO HIGHER CONTACT ANGLE [3].