The characteristics of subionospheric propagation of magnetospheric whistlers have been investigated by means of both digital spectral analysis with high resolution and our field-analysis direction finding measurement for whistlers observed in South China. It is found that very low latitude whistlers, propagated in the Earth-ionosphere waveguide over a distance of the order of 1000 km, exhibit very clear additional dispersion effects near the cutoff frequencies of the subionospheric 1st- and higher-order modes. The additional traces are also found to be left-handed polarized, and when the frequency approaches the cutoff frequencies, the wave polarization becomes very close to exactly left-handed circular and the incident angle becomes nearly vertical. While the whistler components at frequencies away from the cutoff frequencies are linearly polarized. Finally, we emphasize the important use of the subionospheric propagation characteristics in the study of the whistler duct structure, ionospheric transmission of a downgoing whistler and its excitation of subionospheric modes. ¿ American Geophysical Union 1994