A novel conductive nanocomposite system of poly(aniline-co-carbazole)@Fe3O4 was sucsessfully synthesised and dispersed in polydimethyl siloxane (PDMS) matrix to be used as an effective flexible electromagnetic shield in the X-band microwave frequencies. The results from the vector network analizer reveal thet the reflection absorption mechanisem is the dominant. Shielding efficiency up to 12% was measured due to charge transformation between the conductive polymer chain and magnetic nanoparticle interface