Abstract: A locking device for tent poles capable of achieving a firm and easy coupling to poles and easily and conveniently replacing a broken pole piece without replacing the entire pole including the broken pole piece. The locking device includes a mushroom tip member having a fitting portion fitted in one end of a tent pole, a V-shaped longitudinal groove formed on a peripheral surface of the fitting portion of the mushroom tip member, a guide groove formed on the peripheral surface of the fitting portion of the mushroom tip member in such a manner that it crosses the longitudinal groove, and a protrusion radially inwardly protruded from an inner surface of the pole piece corresponding to the end of the tent pole. The protrusion is engagable in both the longitudinal groove and guide groove at the cross point between the longitudinal groove and guide groove.