The present invention relates to high dielectric constant ceramics which can be sintered to maximum density at low temperatures. The ceramic structures consist primarily of a skeleton which constitutes the refractory phase and an interstitial glass which serves simultaneously as a bonding agent and a fluxing agent which enables the ceramic structure to densify in the low temperature range. Among the preferred materials used to form the skeleton are polycrystalline materials which have a high dielectric constant, for example, barium titanate, complex dielectric materials such as lead bismuth niobate and the like. The interstitial glasses required are lead silicate based glasses.