In this paper, outline of the demonstration test for using suction anchor and polyester rope in a floating wind mast (that was converted from floating wind turbine) is presented. After marine soil investigations and specimen test for polyester rope, the basic design methodology for mooring line including polyester rope and suction anchor is presented. Considering the marine soil investigation result, the profile of the suction anchor was determined to be somewhat short and wide dimensions. Installation of the suction anchor was successfully made at both the test site and the targeted demonstration site. Here, a newly developed suction pump system was successfully used. Installation of polyester rope was also made successfully. However, we observed discrepancy in the suction pressure during the installation of suction anchor at the demonstration site, although we did not see the discrepancy at the trial test site.