An endoscopic diagnosis system accurately calculating the oxygen saturation level considering the effects of the blood vessel depth and the blood amount and displaying an oxygen saturation level distribution in simulated colors includes an endoscope device for illuminating a subject, imaging reflected light, and acquiring image signals corresponding to three or more reflected light having a wavelength range of 460 to 700 nm including a first and a second image signal corresponding to reflected light having two wavelength ranges where the light absorption coefficient changes according to the blood hemoglobin oxygen saturation level and a third image signal corresponding to reflected light having one wavelength range where the light absorption coefficient does not change； a blood amount-oxygen saturation level calculator using the acquired image signals for calculation； and a display for displaying an oxygen saturation level distribution based on the oxygen saturation level information.
