Hyperbranched polymers/montmorillonite clay modified with cetyl trimethyl ammonium bromide (MMT-CTAB) nanocomposites with polystyrene core were prepared by self-condensing vinyl polymerization via atom transfer radical polymerization of p-chloromethyl styrene monomer (CMS) alone or with styrene (St) and methyl methacrylate (MMA) monomers in the presence of MMT-CTAB acting as inimer with the double bond at one end and the alkyl-Cl unit at the other end. Three hyperbranched polymers/MMT-CTAB nanocomposites such as PCMS homopolymer/MMT-CTAB, PCMS-b-PSt copolymer/MMT-CTAB and PCMS-b-PSt-b-PMMA terpolymer/MMT-CTAB were prepared. The prepared hyperbranched polymers/MMT-CTAB nanocomposites were characterized via X-ray diffraction, dynamic mechanical thermal analyses and transmission electron microscopy for further applications as dielectric materials. Accordingly, several parameters were measured including dielectric permittivity (epsilon'), A.C. conductivity (sigma) and loss tangent (tan delta) in case of frequency and temperature ranging from 0.1 Hz to 100 kHz and 20-80 degrees C, respectively.