The properties of Pbn(n=2―30) clusters including binding energies, second differences in energy, and HOMO-LUMO gaps, especially fragmentation energies and ionization potentials, have been studied by ab initio calculation. The main fragmentation products of Pbn+ are shown to be Pb+Pbn–1+ for n≤14 and two small cluster fragments for larger ones with n>14. The Pb13+ appears frequently as the products in the fragmentations of large clusters. Also, the calculated ionization potentials of the clusters are consistent with the experiment data.