One of the major areas in organic coatings for corrosion protection of automobile parts is the surface treatment of polyolefin (Polypropylene (RX-2000)) bumper substrates. In order to develop the painting technology, in this work, we directly tried to paint on the plastic bumper substrates without both wet washing process with VOC solvents and phosphate primer spray process. Microwave (MW) plasma treatment represents an efficient, clean and economic alternative to activate polymeric surfaces. O-2 plasma treatment at room temperature within 300 s in the power range of 300-1000 W were used to elevate hydrophilic property of the polyolefin surfaces, resulting in distinctive change of wettability and adhesion between painting layer and polymeric bumper substrates. The treated surfaces have been analyzed using X-ray photoelectron spectroscopy (X:PS) and atomic force microscopy (AFM). Wettability and adhesion properties were elevated by the measurement of the contact angle, adhesion test, impact test, cold resistant impact test and water resistant impact test. We confirmed that the O-2 plasma treatment was a very reliable method for the synthesis of polyolefin substrates with high wettability and adhesion performance. (c) 2005 Elsevier B.V. All rights reserved.