This paper introduced the theory of dehumidifying air conditioning and the packing. Two packed-type dehumidifier with different packing of 350Y and BX-500 was built during the experiment. The results were analyzed. The comparison of the two dehumidifiers was based on the efficiency of the heat transfer and the efficiency of the humidity transfer. The conclusion of the dehumidifying performance of two packing was drawn in the paper. The affection of the ratio of the flow of the solution and the flow of the air to the performance of the dehumidifier was established at last.