Conductive polyurethane composites were prepd. by two-step method consisting in reaction of (p-NCOC6H4)(2)CH2 with oligoetherols and further conversion with (HOCH2CH2)(2), doped with LiClO4 and filled with montmorillonite in twin screw extruder. The composites were studied for structure (FT-IR spectroscopy), mech. and thermal properties and ionic cond. The addn. of LiClO4 resulted in increasing the cond. and deterioration of mech. properties of the composites.