A multi-channel fluorescence measuring optical system and a multi-channel fluorescence sample analyzer using the optical system are provided. The multi-channel fluorescence measuring optical system, which irradiates light onto a plurality of sample channels and detecting fluorescence radiated from samples, includes: a light source (60a-d); an integrator (70) for giving the light irradiated from the light source a uniform intensity distribution; a sample holder (80) having a plurality of sample channels on which the samples (m) are mounted, wherein the samples are exited by the light emitted from the integrator; and a beam splitter (75) between the integrator and the sample holder for dividing the incident light in a predetermined ratio. Since the light intensities of fluorescence images are detected using optical fiber bundles (85a-d) and photodiodes (89a-d), the manufacturing cost can be greatly reduced, and the optical system can be miniaturized.