This paper includes a study on the surface treatments of the barrel of small arms with an aim at improving resistance of corrosion and wear. The inner surface of the barrel is Cr plated or nitrided to improve the performance under the firing. The endurance test was conducted to compare the wear resistance of standard barrel (the non surface treatment barrel), the Cr plating barrel and the nitriding barrel. The wear resistance is evaluated by inner diameter of the barrel, muzzle velocity and dispersion during the firing. And the salt water immersion test was conducted to estimate the corrosion resistance. As the results of the tests, the Cr plating barrel is superior to the NST barrel and the nitriding barrel in a view of corrosion and wear.