An endoscope light source device is constituted by a first light source unit that emits light in a first wavelength band, a second light source unit that emits light in a second wavelength band, a light path combining means for combining the light paths of the light emitted from the first and second light source units, and a light source control means for controlling light emission of the light source units separately. When the light source units are driven to emit light in a first mode, the respective wavelength bands of light are emitted at a first intensity ratio and combined with each other to obtain normal light, which is supplied to an endoscope. Also, when the light source units are driven to emit light in a second mode, the respective wavelength bands of light are emitted at a second intensity ratio having a relatively lower ratio of the light in the second wavelength band, and are combined with each other to obtain special light that has a high light absorption rate in a specific biological tissue, and the special light is supplied to the endoscope.
