Geometric　and　electronic　structures　of　a　series　of　bi-nuclear　niobium　sulfide　clusters,　Nb(2)S0　(n=4-7),　were　investigated　by　the　theoretical　calculations.　Vertical　detachment　energies　were　estimated　based　on　the　generalized　Koopmans＇　theorem　and　were　used　to　simulate　the　anionic　photoelectron　spectra.　The　structural　evolution　behaviors　were　found　to　be　present　in　the　sequential　sulfidation　of　Nb2S＞-/0.　Concretely,　the　additional　sulfur　atoms　tended　to　occupy　the　bridging　sites　of　Nb2S＞-/0　(n=4,　5)　clusters.　Then　varied　poly-sulfur　ligands　(i.e.,　bridging　S0　(n=6,　7)　clusters.　Frontier　molecular　orbitals　were　analyzed　to　understand　the　chemical　bonding.　It　was　found　that　the　highest　occupied　molecular　orbital　of　Nb(2)Scluster,　even　the　sulfur-rich　Nb2S-　cluster,　still　retained　the　Nb-Nb　bonding　features.　The　results　were　compared　with　the　analogs　Mo(2)S0　(n=4-7)　clusters.　The　findings　in　structures　and　chemical　bonding　may　provide　insight　into　the　properties　of　niobium　sulfides,　especially　for　the　sulfur-rich　surfaces.