Sintering behavior and dielectric peroperties of $xCaTiO_3-La(Zn_{1/2}Ti_{1/2})O_3$ system were investigated for better understanding of the microwave dielectric materials. In $xCaTiO_3-(1-x)La(Zn_{1/2}Ti_{1/2})O_3$ systems, solid solution type was focused as a function of composition(x=0.4-0.6) and sintered density. With increasing the sintered density, the relative dielectric constant was decreased and Q value was increased and then saturated. In solid solution type, dielectric constant was increased with increasing $CaTiO_3$ content. In $0.5;CaTiO_3-0.5; La(Zn_{1/2}Ti_{1/2})O_3$ case, dielectric constant(=48) and temperature coefficient of resonace frequency$(=-1 ppm/^{circ}C$) were obtained.