We present and numerically characterize a surface-plasmon-resonance sensor based on an H-shaped optical fiber. In our design, the two U-shaped grooves of the H-fiber are first coated with a thin gold layer and then covered by a uniform titanium dioxide layer to facilitate spectral tuning of the device. A finite element method analysis of the sensor indicates that a refractive-index resolution of up to 5 · 10(3) nm/RIU can be obtained.