Abstract: An fiber optic liquid level indicator with a floating reflector includes a reference scale provided with a reflector disposed in an upper space above the liquid level within a pressure vessel so that a reference distance usable to correct error due to pressure can be calculated on the basis of travel time of a laser beam pulse emitted from a laser generator and reflected from the reference scale reflector through an optical guide and lens. A beam change-over switch is used to selectively guide a laser beam pulse to either the floating reflector or to the reference scale reflector so that pulse travel time can be determined.