Although there are various advantages when high-strength steel is applied to hollow structural section joints, current domestic and international structural design standards prohibit or limit the application of high-strength steel to tubular structures. These restrictions have unclear background and may be excessively conservative. Therefore, the validity of the restrictions on high-strength steel was reviewed through experiments on various types of HSS connections with high-strength steel. The experiment showed that the current strength equation excessively conservatively evaluates the strength of the high strength steel tubular joints, and in terms of ductility and serviceability, the high-strength steel joints showed comparable performance to that of the mild steel. In addition, a design strength equation for HSS joints covering high-strength steels is newly proposed.