The invention provides an electronic endoscope system, a light source device, and a control method of an electronic endoscope system. The light source device (13) is provided with not only a white light source (30) used for obtaining a common observation image, but also a semiconductor light source unit (31) emitting first and second narrow-band domain light in the blue region. The first narrow-band domain light and the second narrow-band domain light are light for obtaining blood vessel information containing oxygen saturation and blood vessel depth. During the obtaining of the blood vessel information, reference signals indicating the luminance level are required for the standardization of cameral signals corresponding to the first narrow-band domain light and the second narrow-band domain light. White light emitted by the white light source (30) is used as reference light for obtaining the reference signals. The determination precision is maintained by the narrow-band domain light of the semiconductor light source, and the cost increase is inhibited by the construction of the existing light source device, that is, the white light source (30).
