Title: Cohen-Macaulay and Gorenstein complexes from a topological point of view Author: Dietrich Notbohm AMS Classification numbers: 13F55, 55R35 Address of Author: Dept. of Mathematics, University of Leicester, University Road, Leicester LE1 7RH, England Email address: dn8@mcs.le.ac.uk Abstract: The main invariant to study the combinatorics of a simplicial complex $K$ is the associated face ring or Stanley-Reisner algebra. Reisner respectively Stanley explained in which sense Cohen-Macaulay and Gorenstein properties of the face ring are reflected by geometric and/or combinatoric properties of the simplicial complex. We give a new proof for these result by homotopy theoretic methods and constructions. Our approach is based on ideas used very successfully in the analysis of the homotopy theory of classifying spaces.