A new desiccant air conditioning system, MCMB : Mesh partitioned Countercurrent Moving Bed, is proposed to achieve an efficient dehumidification at low pressure drop. The dehumidifying section is divided into two flow channels by a wire mesh. Air is introduced from the bottom of one of the channels, while desiccant particles are flowed down in the other channel at a slow speed to achieve updraft type moving bed. Length of the acrylic dehumidifying section is 600 mm with a rectangular cross-section of 50 mm by 5 mm for air flow channel and 50 mm by 10 mm for particle flow channel. Axial distribution of air temperature, T_g, relative humidity, φ, and particle temperature, T_p, are measured and dehumidification rate is obtained. Based on these results, it is found that the MCMB actualizes the efficient isothermal dehumidification at low pressure drop. Furthermore, the wire mesh governs the mass transfer step when the particles have higher adsorption rates such as Zeolite.