Imai suggested a new method to estimate the pressure drag coefficients of bluff bodies at high Reynolds number. He supposed that the flow at high Reynolds number might be obtained by solving a modified Navier-Stokes equation at low Reynolds number which was determined by the assumption of the eddy viscosity in the wake region. In this paper authors discuss the details of the two-dimensional viscous fluid flows past the blunt bodies of arbitrary shape at low Reynolds number ( R =40) by solving numerically Navier-Stokes equations, and investigate the validity of Imai's hypothesis above mentioned. The results obtained are that Imai's idea concerning the flow pattern can be acceptable, and that the pressure drag coefficients of bluff bodies at low Reynolds number agree approximately with those in the high but subcritical Reynolds number range. But that Imai's idea gives invalid informations as to the pressure distribution along the body surface at high Reynolds number.