This volume contains papers presented at the 8th International Conference on Solid State Physics (SSP 2004), Workshop "Mossbauer Spectroscopy of Locally Heterogeneous Systems," held in Almaty, Kazakhstan, 23 26 August 2004. It should be of interest to researchers and PhD students working or interested in recent results in the locally inhomogeneous system investigations by Mossbauer Spectroscopy and the new concepts of data evaluation of complex Mossbauer spectra.