In this work, MOS capacitors were used to study the electrical properties of Mo gate electrode deposited on ZrO$_2$. The workfunctions of Mo gate extracted from C-V curves were appropriate for PMOS. Thermal stability of Mo metal was investigated by analyzing the variations of workfunction and EOT(effective oxide thickness) after 600, 700, and 800 $^{circ}C$ RTA(rapid thermal annealing). It was found that Mo gate was stable up to 800 $^{circ}C$ with underlying ZrO$_2$. The resistivities of Mo were 35$mu$Ω$.$cm∼ 75$mu$Ω$.$cm. These values are lower than those of heavily doped polysilicon. Based on these measurements, it can be concluded that Mo metal gate with ZrO$_2$ gate insulator is an excellent gate material for PMOS.