Finite‐difference simulations are carried out for bifurcated reflected‐shock waves in ionizing argon in a shock tube by solving the thin‐layer Navier‐Stokes equations with ionization reactions. Results are shown for reflection process of an ionizing shock moving at the Mach number of 12 in argon at 400 Pa and 298 K. Computed flow‐fields are compared with snap‐shot shadowgraphs for reflected‐shock waves in ionizing argon. The simulations and the experiments are in good qualitative agreement.