It is important to analyze the hygrothermal processes of building envelopes and the material properties are critical in the analysis. The hygric properties of the commonly used porous building materials in China are insufficient. Measurements on the B07-level autoclaved aerated concrete are carried out at 20~25℃ based on ISO and ASTM standards of static gravimetric tests, pressure plate tests, cup tests, capillary absorption tests and vacuum saturation tests. All the hygric properties have been obtained, including sorption isotherms, the water retention curve, the vapor permeability, the liquid diffusivity, the capillary absorption coefficient, as well as the capillary and vacuum saturated moisture content.