Assuming that the interface of two loosely bonded half-spaces, an elastic solid half-space and a liquid-saturated porous solid half-space, permits a finite amount of slip, the problem of reflection and refraction of plane seismic waves incident on such an interface is studied. It is further assumed that stresses are continuous and a linear relation exists between the shearing stress and the slip across the interface. Numerical results are exhibited in graphical form for different degrees of bonding. Two limiting cases of smooth interface and bonded interface are shown to be special cases of this general problem. It is observed that there is an attenuation of energy at a loosely bonded interface which agrees fairly well with the results of the earlier studies.