Several kinds of silica gel were used to make the different composite adsorbents.The salt content of these composite adsorbents was measured.The corrosion effect was also studied in temperature/humidity equipment.The pore structures of pure silica gel and composite adsorbent were tested.Moisture uptake curves of them were measured.The experiment results showed that as the host matrix of the composite adsorbent，the kind of silica gel impacts on the characteristic of the composite adsorbent.Also the adsorption capacity improves a lot after impregnated salt.The silica gel which is best for the host matrix of the composite adsorbent has the small particle diameter（ranged from 0.5 mm to 1.5 mm）.