The book deals with the application and design of composite steel and concrete structures for buildings according to Eurocode 4. Chapter 1 gives a general overview of the characteristics, design and construction, and applications of composite beams, floors and columns. Also the advantages and disadvantages of the different structural solutions are discussed. Chapters 2 to 5 provide detailed information about the design methods and assessment rules in EN 1994 for composite beams, floors, columns and connections at normal temperature and in case of fire. The Eurocodes assessment rules are explained with many detailed worked examples. Finally, chapter 6 contains a complete calculation of the composite structure of a cinema auditorium consisting of main beams, girders, floors and columns. Composite structures is effective as a book for students or young professionals and as a reference guide to Eurocode 4 for practicing structural engineers.