This paper describes a methodology of earthquake-resistant structural design of the steel-braced multi-story frames specifying the maximum inter-story drift angle. The authors have been studying on a new structural design method of the steel frames with the conventional or ordinal steel braces as the vibration-control devices. It was clarified that the steel braces can reduce the maximum inter-story drift angles in a frame under earthquake through past researches by the authors. Eventually, the paper concludes that the presented design method of the multi-story frames with the ordinal steel braces introducing an equivalent one-mass system is useful and powerful in the specifying-oriented structural design.