In this work, the specific influences of atmospheric pressure plasma (APP) treatment on the surface modifications of poly(ethylene terephthalate) (PET) polymeric film have been explored. The APP was generated using dielectric barrier discharge in the ambient of Ar and N(2)gas mixture. Experimental results of the surface properties are presented for the PET film before and after the APP treatment. The exposure of PET films to APP leads to the roughening surface. Also, the APP-induced modifications are associated with incorporation of polar oxygen and nitrogen containing groups on the PET surface. Due to the changes of chemical composition and topology on the surface by the APP treatment, the contact angle of distilled water on the surface becomes smaller, resulting in higher surface wettability.