The surfaces on the two types of polyethylene terephthalate (PET) fibers, R (Regular grade) fiber and HL (High modulus and low shrinkage) fiber with good dimensional stability for the industrial use were analyzed by contact angle, surface tension and X-ray Photoelectron Spectroscopy (XPS). The surface tension of hydrogen bond contributions γ_s^h of all PET samples was very small value, therefore, these samples were very inactive for the chemical interaction. Regarding surface tension of PET film, the polarity γ_s^p was very small, but the dispersion γ_s^d was major contribution. On the other hand, the polarity γ_s^p of the PET fibers showed very large value, but their dispersion γ_s^d was small. These values were different from those of the PET film. It was estimated that the surfaces of PET R-fiber and HL-fiber might be covered with specific chemical structures with polarity such as ethylene glycol chain or ester bond, respectively different from that of ordinary PET film from the analysis of XPS.