Strengthening of steel structures is necessary to overcome durability problems, to accommodate shortcoming in design and construction process or to increase load bearing capacity. Carbon Fibre Reinforced Polymer (CFRP) is currently one of the most widely used materials for strengthening steel structures. Normally, CFRP strips for flexural strengthening are installed to bottom flange while CFRP strips for shear strengthening of steel beams are applied to web. In this book, the effective methods for shear strengthening were investigated. Comprehensive experimental and numerical studies were conducted to address these issues. In general, it can be concluded that full-covering of the web shear zone with both sides web strengthening gave the best improvement in the load bearing capacity of the strengthened beams. This book includes following chapters: Chapter One: Introduction, Chapter Two: Literature Review, Chapter Three: Experimental Programme, Chapter Four: Developments of Numerical Models, Chapter Five: Results and Discussions, and Chapter Six: Conclusions.