In this paper, polyester fibers (PET) were treated with low temperature plasma firstly. Then, these plasma treated PET fibers were coated with polypyrrole (PPy) by pyrrole deposition polymerization to impart conductive property to the fibers. Interfacial shear strength (ISS) between PET fiber and asphalt was measured by single fiber pull out test. XPS and SEM were used to characterize the fibers’ surface configuration and analysis the functional groups. The results show that plasma-treatment has a strong effect on the surface morphology, surface elements, electrical property and the ISS.