Abstract: Optical waveguide ultramicro-cuvette is an optical device that is made up of cylindrical lens, a sample cuvette of waveguide plate and spherical reflector prism. That it was fitting out with a spectrofluorophotometer(HitachiF-4000) can decreas amounts of sampleto 0 05mL and quadric light absorption from sample. It can avoid photodecomposition of sample too and increase signal-to-noise ratio of instrumet.