We present a project on study of groups composed of dwarf galaxies only . We selected such structures using HyperLEDA and NED databases with visual inspection on SDSS images and on digital copy of POSS . The groups are characterized by size of few tens of kpc and line-of-sight velocity dispersion about 18 km s ^ { -1 } . Our groups similar to associations of nearby dwarfs from Tully et al . ( 2006 ) . This specific population of multiple dwarf galaxies such as I Zw 18 may contain significant amount of dark matter . It is very likely that we see them at the stage just before merging of its components .