Since 1987, we have been studying the liquid-gas two phase fluid loop and trying several kinds of cold plates in order to provide large platforms in the future. This report describes the following in connection with the two-phase fluid loop. An outline of the recent trial manufacture of the two phase fluid loop provided with a bellows-type flow control system, which can be used in space. New type cold plates featuring porous fin. Tests results confirming that the loop and heat exchangers have adequate operational characteristics.