A collecting method of liquid medium and a collecting system of liquid medium in which liquid medium is vaporized by being forcibly brought into contact with a gas and the vaporized medium is condensed. The liquid medium collecting system comprises a means for vaporizing the liquid medium by bringing a gas into contact with a mixture liquid containing the liquid medium and a nonvolatile substance, a means for cooling the gas and the vaporized medium supplied from the vaporizing means and separating them into a condensed medium and a separated gas, and a means for supplying the separated gas, as the above-mentioned gas, to the vaporizing means.