Optical sensors with extraordinary optical transmission phenomenon have proved to hold great potential in the field of chemical and biomedical due to its significant near-field enhancement and high sensitivity to the dielectric environment. However, the utility of this kind of optical fiber sensors is largely limited by its complex nanofabrication methods and expensive instruments. Here to relieve these restrictions, a method of transferring templates was used to process periodic metal nanostructures onto endface of optical fibers. And an experimental setup was built to study sensing characteristics and sensing mechanism of the optical fiber sensors. The obtained results indicated high quality periodic metal nanostructures can be transferred onto endface of optical fibers by the template transfer method. The sensitivity of the resulting sensor to refractive index change was 594.45 nm·RIU-1 (refractive index unit) and figure of merit (FOM) achieved 33.12.