Shape memory polymer (SMP) is being used in many engineering fields due to its shape memory effect and the advantages of large recoverable strain, excellent manufacturability, light weight, low cost and bio-degradability. Therefore it is of practical interest to investigate its thermo-mechanical behaviors. In this paper, a numerical simulation method is supposed to simulate the thermo-mechanical behaviors of SMP using the finite element software of MSC Marc, which is good at simulating the thermo-mechanical behaviors of viscous elastic material. The comparisons between the numerical results and the experimental results by Tobushi et al. illustrate the supposed numerical simulation method well describes the thermo-mechanical behaviors of SMP during the thermo-mechanical processes realizing shape memory effect.