This book is focused on the theoretical and practical design of reinforced concrete beams, columns and frame structures. It is based on an analytical approach of designing usual reinforced concrete structural elements, which is compatible with most International design rules, including for instance the European design rules Eurocode 2 for reinforced concrete structures. The presentation has tried to distinguish what belongs to the structural design philosophy of such structural elements (related to strength of materials arguments), to the design rules aspects associated with specific characteristics data (for the material or the loading parameters). Whatever the design rules considered, the fundamental concept of Limit State will be detailed, and more specifically, the Serviceability Limit State (SLS) and Ultimate Limit State (ULS) both in bending and in compression will be investigated. Some recent researches results including the use of nonlocal mechanics are also presented.