Nanosized TiO2 particles were prepared from titanium (IV) sulfate solution using base solutions at low reaction temperature (95 ℃) and atmospheric pressure by hydrothermal precipitation method without calcination. The effects of preparation conditions, such as kind of base solutions (NaOH, NH4OH, Monoethanolamine, Diethanolamine, Triethanolamine) and surfactants (CTAB, Span 20, SDBS), concentration of surfactants, temperature and pH, on the physical properties of TiO2 particles have been investigated by XRD, SEM and Zeta-potential meter. Absorption area was also investigated by DRS in order to confirm the photocatalytic activity of the nanosized TiO2 particles. It was turned out that, among base solutions, NaOH provides the smallest TiO2 particles with excellent crystallinity. And cationic surfactant (CTAB) prepared smaller TiO2 particles than any other surfactants. When CTAB is added in the concentration ratio of Ti(SO4)2:CTAB=10:1, TiO2 particles with particle diameter of 5.8 nm were prepared. This is approximately 1/10 of that prepared without CTAB.