Abstract: A new"family"of coordination catalysts based on rare-earth for stereos-pecific polymerization of acetylene has been developed for the preparation of high cis(>90%)polyacetylene(PA)films at 30℃. Rare-earth PA was silvery flexible with metallic luster. The highly conducting complexes of rare-earth PA are obtained by do poing with electron acceptors(I₂,Br₂,etc.). The maximum conductivity(σ)of doped films at room temperature is approxima-tely 1000 ohm^-1·cm^-1 for iodine,corresponding to a concentration of about 12.5mol% where σ has increased by some 11 orders of magnitude. The do-ping effect is related to the volume filling fraction of the fibrils of PA.The configuration of polymer and the extent of oxidation of the films also show a certain influences on the doping effect. The resulted polyacetylene-halogen complexes have been characterized using techniques of infrared spectrophotometry, differential scanning calorimetry,x-ray diffraction,scan-ning electron micrography,and electrical conductivity measurements.