In this work, Ge15Sb20Se65 glass is synthesized by the melt-quenching method and then drawn into a bare glass fiber with a diameter of 500 μm. The minimum transmission loss of this fiber is about 1.68 dB/m at the wavelength of 6 μm. A homemade tapering platform allows to taper the chalcogenide fibers into different waist diameters of 20, 100 and 250 μm, respectively. The spectroscopic analysis of the tapered fibers in ethanol solution with different concentrations is presented. Based on the theory of fiber evanescent wave, the sensing characteristics of the tapered fiber in the ethanol solution are simulated by COMSOL Multiphysics software. The results of simulation and experiment are compared and discussed.