An endoscope insertion part that can easily be inserted in body cavities, such as the large intestine, ensuring an enhanced insertability in body cavities without bringing about any pain on patients and a relevant endoscope system. For realization thereof, there is provided an endoscope insertion part comprising an endoscope insertion part body insertable in a test object a spiral tube as a propulsive force generator capable of revolving round the longitudinal axis of the endoscope insertion part body, disposed on the circumferential surface side of the endoscope insertion part body and a spiral part for friction reduction disposed around the spiral tube at given position, for example, base edge side of the circumference of spiral configuration portion as friction reduction means for reducing any frictional force occurring between the spiral tube and an inside wall of body cavity.
