PROBLEM TO BE SOLVED: To provide a rice paddy water level adjusting device consuming the small amount of electricity. SOLUTION: This rice paddy water level adjusting device is equipped with a water gate part 10 built in a water overflowing plate for partitioning between an entering chamber communicating with a flowing in tube 11 and an exit chamber communicating with a water discharging tube 12, and for changing the water overflow level from the entering chamber through the exit chamber, a tubular supporting pole 50 standing straight at the upper surface of the water gate part 10 installed on the upper part of the water gate 10 and a control box 30 built in a receiving part, a controlling part, a battery, a motor, a driving mechanism part, so as to constitute for controlling the motor so that the reading of a potentiometer for detecting the level change of the water overflowing plate agrees with the set water height and cutting off the electric source for the motor and controlling device when the both of them agree each other.
