We investigated the energy,structure and related topological property of beryllium clusters bound by a recently developed first-principles many-body potential(Estela Blaisten-Barojas and S.N.Khanna,Phys.Rev.Lett.,61(1988),1477).A modified cluster structure optimization method based on the genetic algorithms was used to search for the global minimum of the potential.Dependence of the energy,structure and related topological property of beryllium clusters Ben(n=2—25) on cluster size was elucidated;and a systematic structure comparison of Ben with metal cluster Mn and rare-gas cluster LJn bound by long-range Morse potential and Lennard-Jones potential,respectively,was presented.Our results showed that structures of Ben,in the range of n=2—25,can be categorized as either Mn-like or LJn-like,and many-body contributions of the potential appears to play a significant role in determining the most stable structures in beryllium systems.