High quality InAs0.94Sb0.06 films were grown on InAs substrates by the liquid phase epitaxy technique. The structural characteristics and cross-section morphology of InAs0.94Sb0.06 samples were investigated by high-resolution x-ray diffraction measurements and scanning electronic microscopy measurements, respectively. The refractive index and extinction coefficient spectra of InAs0.94Sb0.06 film near the energy band gap were obtained by fitting room temperature infrared spectroscopic ellipsometry with the model of dielectric function in the range of 3 000 to 6 000 nm. The energy band gap of InAs0.94Sb0.06 was 0.308 eV, which was determined by refractive enhancement.