PROBLEM TO BE SOLVED: To provide an underwater anchored object state-monitoring system in which the state-monitoring of an underwater anchored object can be performed inexpensively.SOLUTION: An underwater anchored object-monitoring system is provided for monitoring a state of an underwater anchored object installed in the water or on a surface of the water. The system includes: signal transmitting means 11 provided in the underwater anchored object 1; receiving means 21 provided in a ship 2, and receiving a signal sent from the transmitting means 11; location information creation means 24 for creating location information of the ship 2; transmission means 22 for transmitting the signal received by the receiving means 21 and the location information to a control center 3; receiving means 31 provided in the control center 3, and receiving the signal and the location information transmitted from the ship 2; and state determination means 32 for determining a state of the underwater anchored object 1 from the sign
