Bureau of Indian Standards, Delhi made large number of changes and alterations in IS: 456-2000, Code of Practice for Plain and Reinforced concrete. Realizing the necessity and importance, authors have updated the complete text and presented this subject Limit State Design of Concrete Structures . Ultimate Limit State (ULS- conditions to be avoided) and serviceability Limit State (SLS- limits undesirable cracks and deflections) are two main essential elements of this subject. ULS includes `Limit State of Collapse in compression, in flexure, in shear and in torsion as sub elements. Whereas, SLS includes Limit State of Serviceability for deflections, cracking, fatigue, durability and vibrations as sub-elements. (i) Text for life of concrete structures, fire resistance and corrosion.(ii) For all those, who carry-out their design using computer-programme, authors have given procedures (developed by them) for determining the stress in Hysd-steel bars corresponding to strain developed in concrete.