The objective of the present investigation is to fabricate the CdS based polyaniline (PANI) nanocomposites which are prepared using chemical oxidation technique) with APS as oxidant by the simple polymerization reaction. Further, the chemical structure, morphological study and electrical properties such as FT-IR, XRD, and D.C electrical conductivity analysis are studied. The TEM is used to find the shape and composition of CdS nanoparticle. The electrical conductivity of CdS composite are determined using fore Probe methods. The Activation energy is calculated using the formula of different wt percentages’ of cds nanocomposite and compare the result with bulk Polyaniline.