The Bi2O3-ZnO-Nb2O5 (BZN) pyrochlore thin films were prepared on platinized Si substrates using a reactive rf magnetron sputtering. The structures, surface morphologies, dielectric properties and voltage tunable dielectric properties of films with deposition parameters were investigated. The sputter deposited BZN pyrochlore thin films have a cubic pyrochlore phase and secondary phases of zinc niobate and bismuth mobate when crystallized at 600 similar to 800 degreesC. The dielectric constant and tunability of thin films changed with an O-2/Ar ratio and post-annealing temperature. The BZN pyrochlore thin films sputtered in 15% O-2 and annealed at 700 degreesC had a dielectric constant of 153, tan delta of similar to0.003 and maximum tunability of 14% at 1000 kV/cm of dc bias field under I MHz.