A series of crystalline ZrxTi1-xO4 (x = 0.35-0.65, ZT) powders have been hydrothermally synthesized from double hydrous oxides under moderate conditions. The influences of some factors such as the precursor, pH of medium and anions on the formation of the product have been investigated. The solid-state reaction of TT powder with PbO has been studied. XRD, TEM and other techniques have been used to characterize the product in detail. The ZT powder has a mean particle-size of 10-30 nm and as a precursor appears to have high reactivity to form PbZrxTi1-xO3 (PZT).