The monitoring of museum environment is an effective method for the preventive conservation of precious cultural relics. In order to apply the technique of Internet Of Things in the monitoring of museum environment, the clean concept for museum environment and preventive conservation is described. The characteristics and demands for monitoring temperature and relative humidity, air pollutants, light radiation and harmful beings are analyzed. The successful cases of Wireless Sensor Network technique in several important exhibitions are listed. It is vital to control the risk of museum environment by means of developing the monitoring technique especially suitable for museum environment.