To provide a connecting method for high-strength steel sheets excellent in a fatigue characteristic and provide the high-strength steel sheet suitable for the method by using composite structure steel sheets as materials to be connected, and driving a rivet to connect them mechanically.

Two high-strength steel sheets 1 to be connected are overlapped, a rivet 3 is driven from above by a punch 4 (a), the tip of the rivet 3 is deformed by a die 5 at the time of driving, and two high-strength steel sheets 1 are connected mechanically (b). The high-strength steel sheet 1 to be used has a composite structure including one or more structures of austenite, martensite and bainite and a ferrite structure. The tensile strength is 490-1000 MPa as the mechanical characteristic. The composite structure steel sheet is excellent in ductility, thus cracks are hardly generated by the die 5 when the rivet 3 is driven. High fatigue strength is available at the junction of the high-strength steel sheet 1 as compared with the conventional spot welding method.