Steel material has been used in construction since the 19th century for slender and tall structures, and nowadays has also become an option for smaller buildings and personal residence. This unit teaches you about design and analysis procedures for steel structure members and connections focusing on the seismic design. Furthermore this course will drive you insight the design of suitable bolt and welded connections. First, the types of steel structures for seismic resisting systems are introduced, along with a description of relevant engineering properties of the steel material. Then the course deals with limit states design, tension, bending, shear and torsional analysis of structural steel members; bolted and welded connections; stability; analysis and design of braced and unbraced steel frames. Subsequently, specific information is provided on the seismic design and analysis of two structural types: (i) concentrically braced frames (CBFs) and (ii) moment resisting frames (MRFs). Eventually, fundamental issues for the seismic response of alternative structural systems (e.g., eccentrically braced frames, buckling-restrained braced frames) are introduced and discussed.