Hardened stainless steels are materials widely used in the field of aviation and spaceflight. Machining of this materials with conventional cutting (CC) method is a real challenge compared to other difficult-to-cut materials. Ultrasonic elliptical vibration cutting (UEVC) method is a novel and non-conventional cutting technique which has been successfully applied to machine such intractable materials for the last decade. However, few studies have been conducted on the cutting force in ultrasonic elliptical vibration cutting of hardened materials. This paper presents an experimental study on cutting force in UEVC of hardened stainless steels using cemented carbide tools. Experiments have been carried out to investigate the effect of cutting parameters in the UEVC method in terms of cutting force, while cutting hardened stainless steels. The tests have revealed that the average thrust force,principal force and feed force drop to 3%,10% and 90% of CC value for UEVC of hardened stainless steels. The ratio between the CC force and the UEVC force decrease with the increase of DOC and cutting speed.