Two novel substituted derivatives ( μ3-S)( μ-H)Fe2Co(CO)7Ln (n=2, L=AsPh3 (3) n=1, L=dppm (4)) have been synthesized and characterized by IR, 1H NMR, 31P NMR, MS and X-ray crystallography . The cluster 4 crystallizes in monoclinic space group C2/c, with a=1.589 1(7), b=1.814 9(8), c=2.277 8(11) nm, β=96.861(8), V=6.522(5) nm3, Z=8, Dc=1.552 g·cm-3, F(000)=3 094, μ=12.95 cm-1. Final R indices : R1=0.054 3, wR2=0.101 1. The cyclic voltammetric behavior for the parent cluster 1 and its substituted derivatives were investigated, the results show that the order of σ-donator ability is CO < PPh3 < AsPh3 < dppm. CCDC: 221867.