Shape memory materials are immensely useful because of their capability to recover their original shapes upon exposure to an external stimulus such as heat, moisture, light or a magnetic field. This book reviews key recent research in shape memory polymers, their properties and applications. Topics include the relationship between morphological structures and shape memory properties; high performance Tg and Tm type shape memory polymers; structures of shape memory polymers with supramolecular switches; and the thermally-active and moisture-active shape memory effect of supermolecular shape memory polymers.