Mesoporous ZrO2 powder modified by CeO2 has been prepared by sot-gel method combined with novel heat-treatment without any templates. The morphology and crystal structure were characterized by Fourier transform infrared spectrophotometer (FT-IR), thermal gravimetry/differential thermal analysis (TG/DTA), X-ray diffraction (XRD), Raman spectroscope, N-2 absorption-desorption, scanning electron microscope (SEM) and high-resolution transmission electron microscope (HRTEM). It was demonstrated that the morphologies and crystal structures were varied with the CeO2 content and calcination temperatures. Some circular grooves with diameter about 300-500 nm and thickness of 150-200 nm were observed for 30 mol% CeO2 modified samples. Tetragonal ZrO2 and cubic (Ce,Zr)O-2 solid solution were in turn observed with CeO2 content increasing. The oxygen storage capacity (OSC) of the mesoporous powders was determined by thermalgravimetry (TG) under cyclic thermal treatments. (C) 2012 Elsevier B.V. All rights reserved.