In this study, the structural, electrical and dielectric properties were investigated in (P $b_{0.76}$ $Ca_{0.24}$)[( $Co_{1}$2/ $W_{1}$2/)$_{0.04}$ $Ti_{0.96}$) $O_{3}$ system ceramics which were manufactured with the addition of Mn $O_{2}$. According to the increment of Mn $O_{2}$ addition, tetragonality was decreased. The specimen added with 1.5 mol% Mn $O_{2}$ and sintered at 1150.deg. C showed the highest density of 7.06[g/c $m^{3}$]. The variations of grain xize as a function of Mn $O_{2}$ addition were negligibly small. But grain was grown until 7.88[.mu.m] with increasing sintering temperature. Electromechamical coupling factor planar mode $K_{p}$ was decreased to a small value of $K_{p}$ = 0 in all the specimens added with Mn $O_{2}$ and sintered at 1150.deg. C & 1200.deg. C.& 1200.deg. C.