Viscoelastic behavior has a remarkable impact on the functional realization of shape memory polymers and their composites. Our previous work reported that a series of shape memory epoxies with varied curing agents and contents were synthesized and exhibited higher shape fixture and recovery rates. The viscoelastic behavior of the materials at different temperatures is experimentally investigated in this study. Stress-strain hysteresis under uniaxial tension, stress relaxation, and creep tests are performed. The energy dissipation factor and residual strain factor as functions of temperatures are presented in the basis of stress-strain hysteresis tests. Moreover, the effects of test temperature, curing-agent type, and content on the viscoelastic behavior of these materials are discussed. (C) 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 128: 199-205, 2013