(Pb1-x,Ca-x)(Zr1-yTiy)O-3 ceramics were prepared by the conventional solid-state ceramic technique. The microwave dielectric properties and the microstructures of (Pb1-x,Ca-x)(Zr1-y,Ti-y)O-3 ceramics can be adjusted by varying the composition and the sintering temperature. The replacement of Zr4+ by Ti4+ at the B-site of the ceramics increased the dielectric constant epsilon (r) as well as the temperature coefficient of resonant frequency tau (f), and decreased the quality factor Q (at 4.5 GHz). The effect of PbO loss on the dielectric properties during sintering was also investigated.