In order to contribute to solving the problems of resources and the energy and environment of the earth, the development of high performance materials is required. The development of intelligent or smart materials and their systems is vital since they have various functions, such as sensing, working, and crack-healing by themselves, etc. In intelligent materials, the development of shape memory alloy (SMA) has attracted high attention because of the unique properties that shape memory effect (SME) and superelasticity (SE) possess. If we use the SME and SE in practical applications, not only large recovery strain but also high recovery stress, energy storage and energy dissipation can be obtained. This book describes the mechanical and fatigue properties of SMA, and will be of interest to graduate students, engineers, scientists and designers who are working in the area of electric and mechanical engineering, medical engineering, aerospace engineering, robots, automatic machines, clothes and recycling for the job of research, design, manufacturing and fabrication.