Amylases are one of the most important industrial enzymes. Large arrays of amylases are involved in the complete breakdown of starch. Amylases are of ubiquitous occurrence; however, microbial sources are the most preferred ones for large-scale production. Today a large number of microbial amylases are marketed with applications in different industrial sectors, for example in ethanol and sweetener industry. In the past decade, the encapsulation of enzymes inside inorganic sol-gel matrices has become a generic method to prepare efficient biocatalysts that are easy to recycle. The aim of this work was to study the influence of several parameters on the activity and stability of immobilized bacterial α-amylase, in xerogel. Silica sols were obtained using the following precursors: tetraethoxysilane (TEOS), methyltriethoxysilane (MTES), phenyltriethoxysilane (PhTES). The pH and temperature profiles and the kinetic parameters (KM, Vmax) were determined, in comparison with the native enzyme,.