In order to monitor the real-time soil moisture, temperature and rainfall in remote area where GPRS communication is not accessible, a real-time soil moisture monitoring system was designed by using Iridium communications, real-time information acquisition and Internet technology. The “Internet of Things” architecture was founded and the self-developed Iridium transparent transmission module as well as real-time data acquisition module were designed based on the terminal module 9602 in short burst data (SBD) transceiver. It implemented intelligent, network-based real-time soil moisture monitoring, as well as historical data querying, downloading and text message alarming according to the preset threshold values. Functions such as sensors and communication failure alarm made it possible for safe, steady, reliable communications. Since August 2011, the system came into operation in Shandong Province, Beijing City and other places. System could be safe, stable and reliable to obtain the soil moisture content, temperature and rainfall. The running result indicated that the data transmission system had the advantages of high reliability, low communication fees and wide coverage. The data receiving rate could reach to 97.2 %, and the communication fee was ￥200 Yuan per month, which achieved the aim of longterm monitoring of soil moisture, temperature and rainfall.