Abstract: A liquid level measuring system using a strain-gauge load cell is disclosed. The system includs a buoyancy weight standing upright in a liquid held in an object to be measured in a long bar shape, and having an average density substantially the same as that of the liquid; the strain-gauge load cell producing a change in the buoyancy weight varied with the liquid level as a change of an electrical signal; an amplifier amplifying a voltage signal detected from the strain-gauge load cell; an analog/digital converter converting an amplified voltage signal into a digital signal; a central processing unit applying a driving pulse to the strain-gauge load cell and average-operating a plurality of digital signals to find an average value of the liquid level; and a display displaying the average value of the liquid level as a number.