An optical measurement system of the present invention includes: a probe 3 including a plurality of light-receiving fibers and an irradiation fiber a calibration member 4 including a frame member and a fluorescent body provided in an inner side of the frame member to emit fluorescent light using excitation light having a wavelength in a wavelength band different from a scattering light measurement wavelength band, the calibration member being used while the fluorescent body surface faces a leading end 33 of the probe 3 a fluorescence excitation light source 22b that supplies excitation light to the irradiation fiber a measurement unit 24 that measures each light output from a plurality of light-receiving fibers and a calibration processing unit 27b that calibrates the received light intensity between the plurality of light-receiving fibers based on the measurement result obtained in the measurement unit 24 by measuring light output from a plurality of light-receiving fibers 34 for fluorescent light from the fluorescent body emitted by irradiation with the excitation light.
