Through the experiment on a special designed packed bed, the performances of dehumidification on this packed bed are present in this paper. By testing 3 positions inside the bed, the results are following. During the regeneration process, the average desorption rate of the tail position in this bed is 10.6 g/kg per second, which is respectively 1.93 times that of the fore position and 2.23 times that of the middle position. And for the inlet air of 23 oC, 90% and 1500m3/h, in the stable adsorption process, the adsorbent dehumidification rate of the tail position is 9.51 g/kg per second, which is respectively 2.87 times that of the fore position and 3.51 times that of the middle position. The tail position of the bed holds the best performance both in the regeneration and the adsorption.