We analyze in an homogeneous way a sample of 170 nearby galaxy clusters (z < 0.15) which includes both data from the literature and recent data from the ENACS survey. Under the assumption that mass follows galaxy distribution, we compute cluster masses by applying the virial theorem to member galaxies. The above assumption is supported, a posteriori, by the good agreement between our optical mass estimates and those derived from X-ray analyses, which are free from any a priori assumption about the mass distribution. By resampling our clusters according to the richness class frequencies of EDCC catalog, we obtain the mass function.
