Poly(organoboron halide)-imidazole complex was prepared by hydroboration polymerization of 1,7-octadiene with monobromoborane-methylsulfide complex and subsequent polymer reaction with 1-methylimidazole and methanol. The ion conductive characteristics of the polymer was evaluated by ac impedance method. The optimized concentration of lithium salt was 100 unitmol% to methoxyboron unit. In the presence of lithium bis(trifluoromethane sulfone) imide (LiTFSI), the polymer complex composed of approximately 50% methoxyboron unit exhibited ionic conductivity of 2.59x1O(-5)S/cm at 50degreesC. The lithium ion transference number for this system was calculated to be 0.47, indicating that anions were significantly trapped by Lewis acidic methoxyboron unit.