Polyaniline/Polystyrene composite was prepared in aqueous and aqueous/non aqueous media by polymerization styrene and aniline by using ammonium peroxy disulfate ((NH4)2S2O8) and potassium iodate (KIO3) as oxidant in the presence of sodium dodecylbenzensulfonate (DBSNa) as surfactant. The composite was characterized in terms of morphology, particle size, chemical structure and glass transition temprature. The results indicate that the morphology and particle size of product are dependent on the surfactant and solvent media used. The chemical structure was studied by fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and differential scanning calorimeter (DSC).