A thermally stable mesoporous spherical TiO2 powders with a crystalline framework, high surface area, and large pores was synthesized by novel and simple alkoxide gel-sol method using titanyl acylate gel [Ti(OiPr)4-x(OAc)x] as a precorsor in 0.15N KOH solution. The experiment was performed directly at reaction temperature in the 15℃∼95℃ and atmospheric pressure without hydrothermal process and using the block copolymer. XRD analysis indicates that the anatase and rutile phase were formed pH range in 2∼12 and in below 2, respectively. The synthesized anatase phase was stable up to calcination temperature of 1000℃. The highest specific surface area (BET) was obtained about 232m2/g at the reaction temperature of 55℃. When the calcination temperatures increase, the adsorption-desorption isotherm plot according to the BDDT classification goes from a type IV isotherm to a type II isotherm. The hysteresis loop also exhibit a continuous evolution from type E corresponding to ink-bottle pores to type A cylinder-shapes pores for large particles diameter samples.