Abstract: The problem considered is that of two-dimensional viscous flow in a straightchannel.The decay of a stationary perturbation from the Couette=Poiseuille flow in the douwnstream is sought.A differential eigenvalue equation resembling the Orr-Sommerfeld equation is solved by using a spectral method and an initial-value method (the compound matrix method)for values of the Reynolds number R between O and 2000.The eigenvalues are presemed for several of interesting cases with differentmeasures of mass flux These eigenvalues derermine the rate of decay for the purturbation.