A medical laser light source system including an excitation laser light source apparatus that generates first excitation light having a wavelength greater than or equal to 1.5 μm and less than or equal to 2.2 μm and second excitation light having a wavelength greater than or equal to 1.5 μm and less than or equal to 2.2 μm and differing from the first excitation light with respect to at least one of oscillation energy intensity, oscillation pulse width, repeating frequency, and peak power an optical fiber that is long-distance and propagates the first excitation light and the second excitation light generated by the excitation laser light source apparatus and a laser device that generates laser light having a wavelength of at least 2.7 μm and no greater than 3.2 μm, using at least one of the first excitation light and the second excitation light emitted from the optical fiber.
