This book introduces limit states design concepts for design of steel structures in building following the Egyptian Code of Practice ECP 205. The book starts by simplifying the first step in concept design which is choosing the structural system and presenting it in form of a general layout for the building showing both gravity and lateral load resisting system. Then, it explains the load calculations procedures and the design of different steel elements such as tension and compression members, columns, beams, beam-columns and plate girders. An important aspects in design of any steel structures is the choice, design and detailing of the member connections; thus, the behavior and design of different bolted and welded connections is thoroughly explained along with comprehensive examples. The last part of the book presents design of special elements in end gables and bracing systems. It contains appendices showing the mechanical properties of common hot rolled steel sections and some typical steel details. The book is a very beneficial reference for both practicing engineers and students in senior years of civil engineering programs.