Abstract: Thermoplasticity of Fe-Mn-Si shape memory alloys has been investigated. The experimental results show that the shape memory effect (SME) increases but thermoplasticity decreases with the increasing of Silicon content in Fe-Mn-Si shape memory alloys. Thermoplasticity of these alloys can be improved apparently but SEM not be devastated by adding of microelement Magnesium, because of thermoplasticity being improved by adding of microelement Magnesium.Fe-Mn-Si alloys with 4% Silicon content can be rolled successfully to be seamless steel pipes. So Fe-Mn-Si shape memory alloys show a good applied prospect.