TiO2 catalysts of high surface area and different anatase/rutile ratios have been prepared at low temperature with microemulsion method. The contents of anatase and rutile have been successfully controlled by simply changing the proportion of Cl- and SO42- in aqueous phase of microemulsion. The photocatalytic activity of TiO2 was tested with photodegradartion of Methyl Orange. Anatase and rutile were confirmed having a synergistic effect in enhancing the photocatalytic activity of TiO2 and the catalyst containing 74.2% anatase showed the highest photocatalytic activity.