Ancient Trees Tilting Monitor Sensor is installed in a tree trunk, whose vertical state is normal state. The alarm will be triggered when the trees tilt and the inclination angle is over 10° (configurable). The alarm signal is sent to the monitoring center through wireless transmission. Then, the monitoring center analyzes the data and judges the alarm. The reporting terminal and alarm angle threshold are both configurable. In the normal condition, the terminal sends the report message at the time interval of the periodic report. When the inclination of trees reaches alarm angle threshold, it sends the report message at the alarm report interval.