We simulate supercontinuum generation for various shapes of a dispersion varying As<sub>2</sub>S<sub>3</sub> waveguides on MgF<sub>2</sub> substrate with air cladding. The supercontinuum generation is simulated for pulses of 2000 W peak power and 50 fs pulse width centered at 1.55 μm wavelength. For a uniform waveguide the generated spectrum is considerably narrower than that for a non-uniform waveguide. This is because the non-uniform waveguide allows a continuous phase matching of the generated waves through nonlinear interaction. We have demonstrated that a high coefficient of nonlinear refractive index is necessary for generating supercontinuum with large bandwidths. Larger supercontinuum bandwidth is predicted for waveguides with increasing As<sub>2</sub>S<sub>3</sub> thickness along the propagation direction.