An automatic liquid dispenser is disclosed wherein a liquid adjustor is disposed to prevent liquid from splashing outside of a receptacle, thereby saving the automatic liquid dispenser from being polluted with splashed liquid. A receptacle and level detector emits ultrasound to the receptacle and detects the ultrasound reflected from the receptacle to generate a signal. A controller receives the signal from the receptacle and level detector to control the liquid adjusting unit, and an identifying mark at the receptacle accommodator facilitates the correct arranging of the receptacle.