Ultrafast all-optical switching with switching power of 14 W was demonstrated in a Kerr shutter configuration using a single-mode As2S3 based glass fiber only 48-cm long. The nonlinear refractive index of the fiber was evaluated from the switching characteristics to be n2 = 4.2 x 10(-14) (cm2/W), which is higher by two orders of magnitude than silica glass fiber.