Membranes were used in combination to liquid desiccant air dehumidification to separate the liquid desiccant from the process air to prevent the problems of liquid droplets crossover. In this review, the developments in this relatively new technology were introduced. The membrane materials used for the selective permeation of moisture were described. The design of membrane modules, classified into parallel-plates type and hollow fiber type, were summarized. The key point under research was the modeling of conjugate heat and mass transfer in the membrane modules. Recent researches on the fundamental transport data in the membrane modules were collected and compared. They were useful for future component design and system optimum. At last, the system set up, and the applications of this new technology, were also introduced. It was discovered that the membrane-based liquid desiccant air dehumidification technology was an effective method to overcome the problem of solution droplets cross-over problems. Applications of this technology were promising after these years' accumulation of the insight into the dynamics of system performance and module behaviors.