Environmental humidity plays an important role in maintaining cultural relic stable. Considerations for how to control a particular relative-humidity is one of the main interests in museum. Compared with active humidity control, since the manner of passive humidity control has more advantages in less energy consume, flexible in use, low cost and so on, it has priority to be used in small sealed cabinets or drawers. The researth introduced the primary concept, classification, and mechanism of humidity controlling materials such as silica gel, inorganic salt, organic polymer and comprehensive type, and also summarized the working principle and properties of controlling humidity, the preparation of some materials as well as the up-to-date research progress. Meanwhile, as new self-intellectual property humidity controlling material prepared by chitosan and mineral salt was mentioned. Finally the application prospects and the trends of research and development of humidity controlling composite are put forward.