Plasma polymerization reactions and plasma polymers of xylene/air, xylene/argon, xylene/air/argon, toluene/air/argon, dioxane and allyl cyanide were compared with respect to discharge power (between 50 and 500 W), where all other plasma operational parameters were kept constant. In plasma polymerization, the glow characteristics are known to play an important role depending on the factor W/F,where W is the discharge power and Fis the monomer flow rate. In plasma polymerization reactions, it is known that decomposition of the monomer and/or polymer produced competes with polymer formation. Above a certain power level, polymer decomposition may become the predominant reaction, and hence polymer deposition rates decrease with increasing discharge power. The plasma polymer films were characterized by Fourier transform infra-red spectroscopy, elemental analysis and thermogravimetric analysis. Infra-red spectra of the plasma polymers obtained indicated that when the discharge power was increased, the absorption intensities of all the functional groups decreased. The deposition rates and chemical structures of the plasma polymers prepared appeared to depend strongly on the structure and characteristics of the monomer used and on the conditions of discharge and other operational parameters.