Many kinds of high strength steel for gear materials have been launched in these days. Conventional material tests; e.g., pulsator tests for tooth root bending strength and twin-disc tests for rolling-sliding contact strength, might not accurately evaluate their strength in gear teeth. It is because failure modes which frequently appear on gear teeth made of a high strength steel are not so simple as a breakage and pitting. One of the typical failure modes is as follows: Very hard contacts yield pits on tooth flanks, and cracks initiated at these pits propagate due to tooth bending. Eventually, the cracks lead to a final fracture; e.g., a breakage and flaking. This failure mode could be simulated with contact-bending-fatigue (CBF) tests in which a test piece is subject to a bending stress similarly in the rotary-bending-fatigue tests and a contact pressure similarly in twin-disc tests. The present paper describes the concept of the CBF test and some results which show the CBF test can simulate the mentioned fatigue mode of gear teeth made of a high strength steel.