Rutile or anatase nanocrystals were prepared by a "low temperature dissolution-reprecipitation process" (LTDRP) in HCl or H2SO4 solutions around room temperature. The reprecipitation temperature and organic solvent addition in the solution system greatly affected the phase composition of the final powders. The phase compositional and morphological control of the final powders might be realized by applying a washing operation followed by a hydrothermal treatment in liquid media.