In this study, titania (TiO2) nano powders were synthesized by a new method. TiO2 nano-sized powders were prepared by a gel-casting method. Crystalline structure, morphology and mineral phase analysis of TiO2 powder have been characterized by X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM). Results show that different preparation conditions of gel such as reactants concentration, accelerator, starter concentration, time and temperature of calcination have a large influence on the properties of the produced powder. Calcination time and temperature can improve the crystallization of TiO2 powders and can be an accelerator factor for converting amorphous phase to anatase or rutile phase. The results obtained show that the anatase to rutile transformation is started at about 750oC and the best size of produced powder grain is 20-25 nm.