1-Phenyl-2-[m-(trimethylgermyl)phenyl]acetylene (m-Me(3)GeDPA) and 1-phenyl-2-[p-(trimethylgermyl)phenyl]acetylene (p-Me(3)GeDPA) polymerized with TaCl5-cocatalyst systems to provide in high yields new polymers having weight-average molecular weights over 1 x 10(6). Poly(m-Me(3)GeDPA) was a yellow solid, which completely dissolved in toluene, chloroform, etc., to form a tough film by solution casting. Poly(p-Me(3)GeDPA) was also a yellow solid and partly insoluble in any solvents. The onset temperatures of weight loss for these polymers in the thermogravimetric analysis in air were as high as ca. 400 degrees C. The oxygen permeability coefficient of poly(m-Me(3)GeDPA) was 1100 barrers (25 degrees C), which is about twice that of poly(dimethylsiloxane).