Abstract: An automatic water-sprinkling controller, with a peculiar main-valve connected with water supply, for controlling a water-sprinkling system which includes sprinklers, hose or pipes connected between said main-valve and said sprinklers, and a pilot tube for operating said main-valve. In the automatic controller, when the shortage of water of the ground is sensed by a moisture sensor comprising a ribbon which expands and contracts as a humidity, a microswitch is turned on by the contraction of the ribbon to feed an instant electric current for a electronic circuit and to start a timer circuit. The electric current is instantly fed to a solenoid, which is mounted in a microvalve unit, to open this unit, through the electronic circuit. When the microvalve is opened, a pilot water in the pilot tube, which is connected between the microvalve and the main-valve, starts to flow, and the main-valve is opened.