Vertically aligned single-crystalline TiO2 rutile nanorod arrays were synthesized on FTO transparent conductive substrates, via the hydrolysis of TiCl4 under the co-existence of amino acid catalysts. Using TiO2 seed nanocrystals (prepared from Ti(IV) ethoxide, calcined at 450 degrees C for 1 h), TiO, rutile nanorod arrays grew at a relatively mild temperature of 95 degrees C for 2 days. The growth speed and morphology of nanorod array were controllable by changing the type and concentration of amino acid. XRD analysis revealed that the TiO2 nanorod arrays were composed of highly crystalline rutile phase even without calcination. Preliminary dye-sensitized solar cell performance was also reported.