A  silicate  catalyst prepared which has a mezopore type   (MCM-41) ,by manner that condensation where the interaction between Tetra Ethyl Ortho Silicate (TEOS) with 3-Mercapto Propyl Tri-methoxy Silane (MPTS), in the presence of superficial active substance {Cetyl Trimethyl Ammonium Bromide(C ₁₆ TAB)}at room temperature.{11,9}. The process of changing the  surface hydophilic of the catalyst has done by using substance(trimethylchlorosilane), which symbolized by the symbol (TCMS). calibration results had shown that the number of acidic  sites equals (0,633mmol/lit), the specific surface is equal to (1500m²/gr), the graph lines belonging to the adsorption and desorption of nitrogen showed: decreasing the voleume of adsorbed nitrogen with increasing applied pressure whenever sample hydrophilic increased. {8}Then we applied The Fischer esterification  reaction  between a carboxylic acid(Benzoic Acid) and an alcohol(Mythanol) to give an ester (benzoate).  according to the reference method, as a model for the interaction in an aqueous medium, by using catalyst which prepared in this research before and after changing its hydrophilic (13).