The effect of calcining temperature on planar coupling factor Kp resonance and antiresonance frequency of $Pb(Z_{0.53}Ti_{0.47})O_3$ doped with $Nb_2O_5$ has been investigated. The calcining temperature ranged from $700^{circ}C$ to 110$0^{circ}C$ The calcining temperature affected on antiresonance frequency more strongly than the resonance frequency. Therefore the Kp was almost entirely dependent upon the antiresonance frequency. The p and antiresonance frequency of the sample in creased with the calcining temperature reaching a maximum at about 90$0^{circ}C$ When a poling electric field of 35KV/cm was applied to the sample calcined at 90$0^{circ}C$ and sintered for two hours at 120$0^{circ}C$ Kp attained a maximum value of 0.64 which is in good agreement with the results of other investigators.