The effects of two drying methods namely spray drying and freeze drying on adsorption isotherms and thermodynamic properties of mulberry powders were investigated. The effects of two drying methods on glass transition temperature (T_g) and storage stability of mulberry powders were also compared and discussed. The results showed that the adsorption behaviors of mulberry powders followed Ⅲ type isotherms. Blahovec-Yanniotis model achieved the best fit to describe the absorption behaviors of mulberry powders. The net isosteric heat and differential entropy of mulberry powders decreased with increasing moisture content, and then gradually kept constant. The spreading pressure of mulberry powders decreased with increasing temperature, but increased with increasing water activity (a_w). The integral enthalpy of mulberry powders decreased with increasing moisture content and gradually constant. The integral entropy of mulberry powders decreased first (reached the minimum) and then increased rapidly with the increasing of moisture content and then tended to be stable. The moisture adsorption of mulberry powders followed the enthalpy entropy complementary theory and the process was enthalpy driven and non spontaneous process. When the moisture content/ a_w is the same value, the net isosteric heat, differential entropy and entropy integral of spray-dried powders were higher than those of freeze-dried ones, but the integral enthalpy of spray-dried powders was lower than that of freeze-dried ones. The T_g of mulberry powders decreased with increasing moisture content. When the moisture content is the same, the T_g of freeze-dried powders was higher than spray-dried ones. At 25 ℃, critical water activity of spray-dried and freeze-dried powders were 0.0952 and 0.1151, respectively. The critical moisture content of spray-dried and freeze-dried powders was 0.0761 g/g and 0.0792 g/g, respectively.