More and more attention has been paid to the enthalpy exchanger (or total heat exchanger). The function layers, which exchange the heat and water between fresh air and exhausted air, play a demanding role in improving efficiency of the exchanger. Paper with low cost and high mechanical property is widely used as the function materials in the current enthalpy exchangers. In this study different materials have been prepared by spraying the thin paper layer with the calcium chloride solution and drying in the oven to improve the hygroscopicity of the material. The solution concentrations are 5%, 10%, 20%, 30% and 40%. The exchangers made by the modified function layers and normal structural layers are applied for test on the base of the GB standard test condition. In the case of the 0.3m/s (corresponding to 50CMH), the biggest absolute enhance of temperature efficiency, latent efficiency, enthalpy efficiency are 15%, 26%, 24% in heat condition and 23.6%, 21.8%, 22.1% in cooling condition. On the other hand, the pressure drop of the air through the exchanger increases 5 Pa in heat condition and 8 Pa in cooling condition, and it is not difficult for total heat exchanger to overcome the problems caused by increase of pressure drop