Precipitates in different structures were prepared by the hydrolysis of a TiCl4 solution at room temperature and 70degreesC. The pH effect on titania-phase transformation was investigated. The original precipitate formed by the hydrolysis of titanium tetrachloride formed a gel-like structure at pH 4 with the addition of NH4OH, which could be changed to essentially 100% rutile phase at 600degreesC. The rutile precipitates prepared at 70degreesC could be changed to mixed-phase product at pH 0.50 and total anatase phase at pH 3.13 and 5.15. Complete phase transformation from anatase to rutile occurred in the three samples at 700degreesC.