The general expressions for the retroreflective power coupling coefficients of a fiber coupled with a reflector have been derived for propagation of both incoherent light and a laser beam Gaussian beam. Furthermore, expressions of retroreflective power coupling coefficients for several different reflectors coupled with the fiber and when the reflector is moved along the axis of the fiber-reflector system are also shown. Curves of the retroreflective power coupling coefficients for both fiber-plane mirror and fiber cat's eye refleotor systems have been measured experimentally.