Abstract: A novel interferometer is designed based on the dispersive property of slow light media. The numerical simulation on its physical process proves that the spectral sensitivity of interferometer can be enhanced effectively using the slow light medium. And the sensitivity is proportional to the group refractive index of the slow light medium. A further investigation gives the general method of designing slow light interferometers taking into account the dispersive property of GaAs. It is theoretically demonstrated that the spectral sensitivity of an interferometer can be greatly enhanced by dispersive property of semiconductor GaAs in nearinfrared region.