Abstract: In order to approach the influence of TiO₂configuration on photocatalysis,the photo-catalytic degradation process of methyl-orange by TiO₂which was prepared by adsorption phase reaction technique and impregnation methods was studied.The influence of preparation conditions on the morphology and activity of TiO₂was also investigated.After analyzing the reaction,it assumes that the diffusion and surface reaction are coupled.The controlling step depends on the activity of catalyst and the concentration of methyl-orange.It affects the apparent order of the reaction.After evaluating the activity of catalyst,it is deduced that the key factor affecting the photo-catalytic activity is the type of crystal of TiO_2,secondly the content of Ti and diameter of the particles.The catalyst prepared by adsorption phase reaction technique has a larger content of Ti,smaller diameter,and can be better controlled,thereby better photo-catalytic.With the increasing of water content,the advantage of adsorption phase reaction technique is becoming more and more conspicuous.