A network microstructure with large grains isolated from one another by the regions constituted with the agglomerated fine grains of CCTO ceramics fabricated by sol-gel processing has been investigated. The temperature dependence of dielectric properties associated with the contribution of grain below 90 degrees C, grain boundary in the temperature range of 90-250 degrees C, and electrode interface above 250 degrees C has been demonstrated under 10 kHz from room temperature to 400 degrees C and the presence of dielectric diffusion behavior above room temperature is clear. Also, the pyroelectric properties have been measured up to 250 degrees C so as to eliminate the effect of electrode interface and the incidence of the pyroelectric effect associated with the temperature dependence of pyroelectric coefficient implies that CCTO has a vast potential in the field of high-temperature pyroelectric sensing without induced applied bias. (C) 2010 Elsevier B.V. All rights reserved.