Abstract: The crystal of [(C₂H₅)₄N]₃{[(SCH₂CH₂S)MoSs]₂Fe} was obtained by the reaction of [(C₂H₅)₄N]₂ MoS₄, FeCls and ethane-1, 2-dithiol in MeOH-MeONa. The crystal structure of the compound was measured by X-ray.The crystal belongs to the monoclinic system, it crystallizes in space group Cc with a =14.0030Å, b=18.3970Å, c=17.5705Å, β = 96.458°, V=4497.6ų and z = 4. The structure was refined by least-squares. The value of Rwas 0.052. The compound possesses activity of acetylene reduction with KBH₄ as reductant, it displays good activity of acetylene reduction with reconstitution of uw45. The characters of IRuv-visible, ¹H NMR, EPR, Mossbauer spectra and magnetic susceptibility of the compound have been investigated.