Abstract: The initial intention of this study is to prepare silica xerogels using a-two step acid base catalyst method based on sol-gel process. It is then followed by studying the fundamental parameters that govern the silica material structure from the perspectives of the chemical composition and surface properties. This method was employed to control the ratio of the silanol:siloxane concentration on silica xerogels. Specifically, the surface silanol groups are hydrophilic in nature which can coordinate with water molecules via hydrogen bonding. Through this interaction, the coordinated water undergoes hydrolytic attack on the neighbouring siloxane bridges which are easily hydrolyzed. FTIR spectroscopy showed the higher the sol pH the greater the siloxane concentration of the as-prepared xerogels. In addition, the surface structure of silica xerogels was pH dependent which showed a shift from microporous to mesoporous structure (2.57–17.67nm). The results obtained in this investigation are very useful to the understanding of the material matrix which is crucial for the fabrication and performance of the silica based membranes. Keywords: Silica Xerogel, Sol Gel, Acid-Base Catalyst, Silanol, Siloxane