Abstract: The technology of liquid desiccant and solar regeneration, is the key technical problems of evaporative cooling in high temperature and humidity region. Through the experimental measurement, the relationship between the density and the different quality percentage of calcium chloride (CaCl2) and chloride lithium (LiCl) mixture liquid (molar ratio of 1:1) was studied. Also the relationships between the import of air temperature, humidity, air flow, salt solution flow, the solution quality concentration, water vapor pressure difference and the dehumidification were studied. The conclusion is that density of the mixture is very approximate to that of the solution component (CaCl2), and the important effect element of dehumidification is the differential pressure between the heat and mass transfer process in the air and solution. According to the experimental research of Ertas, the author got the vapor pressure calculation formula of the mixture calcium chloride (CaCl2) and chloride lithium (LiCl) with quality percentage of 20%-40%, and the formula of the differential vapor pressure and the dehumidification. This research provides a new thinking for dehumidifying technology of greenhouse facilities and livestock and poultry houses.