A scanning endoscope system includes: a scanning endoscope including a light-guiding section that guides illumination light, a driving section that causes the light-guiding section to swing such that an irradiation position of the illumination light draws a trajectory corresponding to a predetermined scanning pattern; and a light-receiving section that receives return light of the illumination light; a test chart device including a plane portion having first and second regions; a light detection section that outputs a signal corresponding to an intensity of the return light; a pixel generation section that generates pixels on the predetermined scanning pattern; a first correction value calculation section that calculates a correction value based on a pixel value of each of the pixels in the first region; and a second correction value calculation section that calculates a correction based on a pixel position of each of the pixels in the second region.