A solvothermal method is described for preparing nanomaterials of titanium dioxide (TiO2) while controlling the growth of rod-shaped nanomaterials. Titanium (IV) isopropoxide (TTIP) and butyl ether were chosen as the precursor and solvent, respectively. Oleic acid and decanoic acid were used as the surfactant. TiO2 nanospherical particles and nano-rods were synthesized in mass quantities by adjusting the kind of surfactant, the concentration of the precursor, and the solvothermal reaction temperature. The synthesized TiO2 nanospherical particles and nanorods were uniform and transparent in the toluene. The TiO2 nanospherical particles were about 3.5 nm in size. The TiO2 nanospherical particles and nanorods were of a highly crystalline anatase structure. The direction of growth of the TiO2 nanorods was [001] and the band gap energy of the TiO2 nanorods, evaluated by optical absorption, was 3.34 eV.