Epoxy coatings containing different volume fractions of ultra-short glass fibers were prepared successfully. Ultra-short glass fiber not only can improve the hardness, adhesion of the coating, and glass transition tem-perature （Tg）, but also can decrease the coefficient of thermal expansion （CTE） of the coating. Electrochemical impedance spectroscopy （EIS） was used to evaluate the barrier properties of the coatings containing different volume fractions of ultra-short glass fibers. The EIS results showed that the coating had the best barrier property when it contained 20% （volume fraction） ultra-short glass fibers. The functions of the ultra-short glass fibers in epoxy coating are two fold： first, they can improve the coating mechanical properties as reinforcement materials; second, they parallel to the substrate and inhibit the corrosive medium to pass through the coating.
