Abstract: The seepage is one of the main ways of radon migration in the fragmented media, so it is of great significance to study radon seepage migration and exhalation laws in the fragmented emanation media for the design of radon protection. The uranium ore particles whose diameters were from 4 mm to 5 mm were chosen as the experimental samples, and a home-made one-dimensional seepage experimental device was used to study the variation of pore radon activity concentration in the fragmented emanation media and the variation of radon exhalation rate in the surface of fragmented emanation media at different seepage velocities. The experimental results show that the gas permeability is quite large in the fragmented emanation media, so the seepage becomes the main force of radon-migration. When the main way of radon migration is seepage, by measuring the pore radon activity concentrations under different seepage velocities at a fixed position or at different positions under a seepage velocity, the free radon production rate can be estimated according to the analytic equation of radon activity concentration distribution in the emanation media and the non-linear least square method. Within the range of certain seepage velocity, the radon activity concentration at a position decreases with negative exponent along with the seepage velocity increase, and the radon activity concentration under a seepage velocity increases approximately linearly along with the distance from the media seepage inlet. The radon exhalation rate on the surface of the media seepage outlet increases exponentially with the seepage velocity, and gets stable at last.