A ferromagnetic layered composite ABAB....ABA is studied by means of Green function approach. Our attention is focused on the elementary excitations and low temperature magnetisation behavior. In the presented paper we take also into account the eects of damping due spin-spin interaction. As a result not only the positions and relative intensities of resonance peaks are obtained, but also the resonance line-width is found. On the basis of Green function method the temperature dependence of magnetization of a ferromagnetic layered composite is calculated and the spin wave parameter B in the Bloch's law T 3/2 is found and presented in dependence of parameters characterizing the system under consideration.