Abstract: The polyaniline microtubules were prepared by using an in-si tu doping method. The polyaniline microtubules with the dielect ric loss properties were composed with the carbonyl iron with the magnetic loss properties.The elect romagnetic properties of the composite were studied. The results show that the elect romagnetic parametercan be adjusted through changing the mass ratio of carbonyl iron to polyaniline microtubules in the composites whenthe mass ratio of paraffin wax to the composites of carbonyl iron/ polyaniline microtubules is constant at 1 ∶1.