Abstract: Provided is a groundwater monitoring system using an IoT-based LiDAR sensing technology, including: one or more LiDAR sensing devices each installed on the upper periphery of a groundwater well to measure a groundwater level and thus transmit data values including the measured groundwater level to the outside; and a management device for receiving the data values from the LiDAR sensing devices and thus storing and managing the received data values. Each LiDAR sensing device may include: a GPS sensor for recording position information, based on satellite signals; a measuring sensor for emitting a laser beam vertically and downwardly to measure the groundwater level and thus produce groundwater level information; a memory for integrating the position information and the groundwater level information with each other as one data value and storing the data value; a communication part for transmitting the stored data value to the outside; and a power supply part for supplying the power for the operation thereof.