We present a novel design for a miniature and low-cost Surface Plasmon Resonance (SPR) sensor chip for which we employ the polymer optical waveguide fabrication technique. The chip is 12.5 mm × 30 mm with four measurement channels. This SPR sensor chip can detect changes in the refractive index of an analyte by measuring the SPR wavelength shift in the spectra of transmitted light. We evaluated the SPR refractive index sensitivity of this device for liquid sample.