In this study, microstructural, dielectric and electrical properties of (Pb$sub$0.83/) (La$sub$0.2/Ce$sub$0.8/)$sub$0.08/TiO$_3$(PCT) ceramics as a function of MnO$_2$ addition and electrode size variation were investigated for 30 MHz high frequency ceramic resonator application. Grain size was gradually increased according to the increase of MnO$_2$ addition amount. Moreover, the density showed a constant value with increasing MnO$_2$ addition amount. Dielectric constant was decreased with increasing MnO$_2$ addition amount. Curie temperature of all the composition ceramics was nearly constant around 330$^{circ}C$. The maximum D.R.of 50.5 dB and maximum Q$sub$mt3/ of 1842 in the 3$^$rd/ overtone vibration mode were appeared at the composition of 0.3wt% MnO$_2$, respectively.