Abstract: A cylinder bore for minimizing the friction loss may include a plurality of oil pockets formed on stroke sections that contact a piston on an interior circumference of the cylinder bore. The oil pockets may be formed by a laser honing method, and may have different shapes over the stroke sections or different shapes over the stroke sections according to stroke speeds. Moreover, the oil pockets may have a structure such that more oils can be supplied to an upper stroke section or to a lower stroke section than to a center stroke section of the cylinder bore. Furthermore, the oil pockets may be formed symmetrically with respect to a center stroke section of the cylinder bore.