A novel functional polyacetylene containing fluorene group as a pendant,poly(2-(p-methylstyrene)-7-acetylene-9,9-dioctyl-fluorene), was synthesized in moderate yield by[Rh(nbd)Cl]_2-Et_3N catalyst.The structures and properties of monomer and polymer were characterized and evaluated with FTIR,NMR,UV-vis,GPC and Z-scan,respectively.The results show that the incorporation of fluorene into polyacetylene has endowed the resultant polymer with well optical limiting properties for laser at wavelength 780 nm based on two-photon absorption mechanism.