An extension portion extending outwardly is integrally formed on the edge of an end portion of an exhaust pipe; a collar is fixed on the outer periphery of the end portion of the exhaust pipe by caulking; and the edge of the outer end of the collar is abutted against the extension portion. The aforementioned arrangement provides a connection portion of an exhaust pipe for an engine which is intended to rigidly connect the exhaust pipe to an exhaust port of the engine, to prevent gas leakage by eliminating the occurrence of clearance at the connecting portion, to reduce the flow resistance of exhaust gas in the exhaust pipe, and to reduce the production cost of the connection portion.