Titanium dioxide was synthesized by the hydrolysis of titanium tetraisopropoxide (TTIP) in the presence of acetic acid, 2-propanol, and organic amines (octylamine, aniline, and isobutylamine). H 2O was supplied by an esterification reaction between acetic acid and 2-propanol (denoted as H 2Oe), and/or by intentionally adding it (denoted as H 2Oa). It was found that the quantity of H 2Oa plays a crucial role in the morphology and porous structure of the final TiO 2 product. Without the addition of H 2Oa, 1D and porous TiO 2 was synthesized. With the addition of H 2Oa, and when the H 2Oa:TiO 2 molar ratio was in the range of 1:1 to 60:1, macroporous TiO 2 microspheres possessing a large surface area and high thermal stability were obtained. When the H 2Oa:TiO 2 molar ratio exceeded 60:1, porous TiO 2 with an irregular shape was formed. The variation in the morphology and porous structure is attributed to the manipulation of the growth kinetics by the addition of water.