The relation is examined theoretically and experimentally between viscous stress and strain rate in a steady shock front propagating in aluminum materials. A theoretical method is used to obtain the temperature and the equilibrium stress distributions in a steady shock front. The analytical temperature in the absence of viscosity is compared to that in the absence of heat conduction to clarify features of the distribution. The shock viscous stress distributions are estimated from the stress on the Rayleigh line and the analytical equilibrium stress. In the experiment, the flat-plate impacts of 6061-T6 aluminum are carried out by a light gas gun. The free-surface velocities are measured by a velocity interferometer system (VISAR). The strain rate in a shock front is estimated by using the experimental velocity data. As compared the distribution of the analytical shock viscous stress to that of the experimental strain rate, it is found that there is the analogical profile for the strain. From those results we also examine a hybrid numerical simulation.