It is proved that a cyclically (k - 1)(2n - 1)-edge-connected edge tra
nsitive k-regular graph with even order is n-extendable, where k great
er-than-or-equal-to 3 and k - 1 greater-than-or-equal-to n greater-tha
n-or-equal-to inverted right perpendicular (k + 1)/2 inverted left per
pendicular. The bound of cyclic edge connectivity is sharp when k = 3.