Lead lanthanum zirconium titanium stannate (PLZST) has been synthesized by a modified coprecipitation in a polyvinyl alcohol (PVA) aqueous solution. X-ray diffraction (XRD) study shows single perovskite phase formation at 650°C for 2h. The average particle size of calcined powder was about 70nm. The green pellets have been sintered at 1000°C, 1050°C, 1100°C and 1150°C for 2h, respectively. Effect of sintering temperature on microstructure and dielectric properties has been investigated. Dense ceramics with average grain size about 2μm were obtained at the relatively low temperature of 1050°C for 2h and dielectric constant of 1633 at 1kHz has been observed. Also, a comparison of particle size and sintering process is made between the samples prepared by the modified coprecipitation and the conventional coprecipitation.