  The mean redshift of the core of the Coma cluster - cz = 6953 km s^{-1} and
its dispersion \sigma=949 km s^{-1} are obtained by means of the analysis of
the substructures of this cluster by using the S-tree method. The existence of
three subgroups of galaxies is revealed, one of them is associated with the cD
galaxy NGC 4874, the other -- with NGC 4889. It is argued that these subgroups
are {\it galaxy associations}, i.e. galactic dynamical entities moving within
the main cluster. Thus we conclude that the non-stationarity of the dynamical
processes ongoing in the Coma core is due to the merging of small-scale galaxy
associations, rather than of two equal sized clusters. We provide the lists of
the galaxies of the associations, the observational study of which can be of
particular interest.
