Novel pi -conjugated boron polymers containing transition metals in the main chain were prepared by hydroboration polymerization between tetrayne monomer including metal complex and tripylborane. From gel permeation chromatographic analysis (THF, PSt standards), the number-average molecular weights of the polymers obtained were found to be 9,000. The polymers were soluble in common organic solvents such as THF chloroform and benzene. The absorption peaks due to pi-pi* transition were observed around 390nm in the W-vis spectra of these polymers. The fluorescence emission spectra exhibited intense peaks at 490nm (in chloroform, room temperature, excitation wavelength at 390nm).