Ultrafast nonresonant third-order optical nonlinearity of the O.64GeS 2-O.16Ga2S3-O.2CsCl chalcohalide glass, utilizing the femtosecond time-resolved optical Kerr effect (OKE) technique, is presented. The experiment aims to find out a larger optical nonlinear material with ultrafast response time and no TPA at the optical telecommunication wavelengths. The homogeneous glasses were obtained through air quenching and subsequently annealing at the temperature a few degrees below the glass transition temperature. Homogeneity and amorphous characteristics of the prepared bulk samples were confirmed by optical and electron microscopy and X-ray diffraction (XRD) patterns. The experiment also shows that the glasses have the potential applications in the photoelectric fields such as all-optical switching devices.