A scanning endoscope system includes: a scanning endoscope including a light guide portion that guides an illuminating light, a drive portion capable of causing the light guide portion to swing so that an irradiation position of the illuminating light draws a locus corresponding to a predetermined scanning pattern, and a light receiving portion that receives a return light of the illuminating light a light detecting portion that outputs a signal corresponding to intensity of the return light and a control portion that performs control for driving the drive portion to sequentially perform a first scan in which the irradiation position of the illuminating light moves toward a center point from an outermost point of the locus in a spiral shape and a second scan in which the irradiation position of the illuminating light moves toward the outermost point from the center point of the locus in the spiral shape, and perform a third scan in which the irradiation position of the illuminating light circles on the same circumference.
