Currently little is known about the mass distribution on intermediate scales between those probed by deep redshift surveys of galaxies and those probed by COBE. Catalogs of galaxy clusters reach depths of several hundred megaparsecs, and, thus, are very useful for those scales. Only the Las Campanas Redshift Survey (LCRS) is comparable with that depth. However, the LCRS samples only narrow slices whereas cluster catalogs cover a large fraction of the sky. Clusters seems to be the most suitable objects to fill the gap between scales probed by COBE and the galaxy samples. Moreover, clusters are advantageous over galaxies as probes of the matter distribution in the Universe because our understanding of its formation and evolution is better established than it is for galaxies. Clusters are high peaks (mass scale M ≃ 1015
⊙) in the density field, which have collapsed relatively recently. Because of that, it is easy to identify clusters in numerical simulations. But the number of clusters is much smaller than the number of galaxies, which makes the statistics of clusters noisier. Nevertheless, clusters are exceptionally useful objects for the investigation of the matter distribution on scales well above 100 h
–1 Mpc. Thus, it is worth to apply different statistical tests to these objects.