This paper describes synthesis of novel organoboron polymers by hydroboration polymerization of bisallene compounds. The polymers were prepared by polyaddition between thexylborane and bisallenes. The polymers obtained have allylborane units in their main chains and can be expected as a novel type of reactive polymers. The polymer was subjected to a chain transformation reaction and the corresponding polyalcohol was obtained. Hydroboration polymerization of bisallene with mesitylborane was also carried out. It was found that the polymer prepared from mesitylborane showed higher stability than that prepared from thexylborane.