The present study investigated the dispersion of floating particles in a Taylor vortex flow reactor experimentally and numerically. The working fluid was glycerin solution and had a density (rho(f)) of 1210 kg . m(-3) and a viscosity (mu) of 0.1 Pa . s. Floating particles of an acrylic resin had a density (rho(p)) of 1190 kg . m(-3). Two groups of particles with mean diameters of 710 and 974 mu m were discerned. Although particles penetrated the Taylor vortex flow region in the axial direction at different rotational Reynolds numbers, particle segregation was observed. It was confirmed that the smaller particles penetrated deeper in the axial direction. Numerical simulations were also conducted to elucidate the mechanism of particle segregation. Numerical results of a particle-tracking method indicate that the small particles moved on the outermost orbit of a torus. Results of a distinct element method suggest that interparticle collision affected particle transference between vortices.