Zirconia samples and ZrO2-TiO2 solid solutions were synthesized from zirconium and titanium alkoxides with the Zr/Ti molar ratios of 1:0, 9:1, 6:1, and 3:1 by various methods, i.e., glycothermal method using 1,4-butanediol or ethylene glycol, alkoxide method, and solvothermal treatment of the alkoxide-derived hydroxide sol. The samples were characterized by XRD, TG-DTA, Raman spectroscopy, and nitrogen adsorption isotherm. In all the samples, ZrO2-TiO2 solid solutions were obtained in which Ti was incorporated into the ZrO2 lattice. The ZrO2-TiO2 solid solutions had higher thermal stabilities and much larger surface areas than ZrO2.