A method for remotely monitoring persons and their behavior applies to a person wearing an electronic device which is tracked. The method includes sensing posture and changes in posture of the person within a tracking area to generate posture sensing signals, acquiring wireless signals of the electronic device and further obtaining changes in position of the person according to signal strength of the wireless signals of the electronic device, and transmitting the posture sensing signals and the changes in position of the person to at least one server to analyze and identify the position and behavior of the person and issue warning to caregiver if appropriate. A behavior tracking device is also provided.