A large figure-of-merit (FOM) piezoelectric transducer has been developed based on a Pb(Mn,Nb)O3-Pb(Zr,Ti)O3 (PMnN-PZT) epitaxial thin film on a Si substrate for MEMS (Micro Electro Mechanical Systems) sensors such as vibratory gyroscopes. A c-axis oriented PMnN-PZT thin film was epitaxially grown on a Si substrate covered with buffer layers by sputter deposition with fast cooling. This film has excellent properties of a large piezoelectric coefficient (e31,f, ∼-14 C/m2), a small dielectric constant (εr33, ∼200), and high Curie temperature (Tc, >500 °C) compared to PZT-based bulk ceramics. The calculated FOM for piezoelectric MEMS gyroscopes reached 110 GPa, which is 5 times larger than those of conventional PZT polycrystalline thin films. We believe that the epitaxial PMnN-PZT/Si transducer has a great potential for high performance piezoelectric gyroscopes.