A method for monitoring slope lands and buildings on the slope lands includes installing a light transceiver on a slope land and a light emission device on a location or a building corresponding to the light transceiver. When light emitted from the light emission device is received by the light transceiver, the light transceiver does not output signals. The light transceiver does not receive the light emitted from the light emission device when the dislocation or inclination occurs to the slope land and the light transceiver outputs a signal to alert a monitor center.