Abstract Novel poly(ferrocenylnbutylmethylsilane) with unsymmetrical silicon substitution groups [Fe(η-C5H4)2(SiBuMe)]n (PFBMS) (6) have been prepared via the thermal ring-opening polymerization (ROP) of the corresponding strained silicon-bridge [1] ferrocenophanes [Fe(η-C5H4)2(SiBuMe)] (4) and via the nucleophilic substitution of poly(ferrocenylmethylchlorosilane) [Fe(η-C5H4)2(SiMeCl)]n (5) with n-butyllithium. Resultant PFBMS was structurally characterized by 1H NMR and UV/visible spectroscopy. The molecular weights of PFBMS (6) were measured by gel permeation chromatography (GPC) using polystyrene standard, and the solution electrochemical behavior of PFBMS was investigated by cyclic voltammetry (CV).