Internal friction and elastic modulus of Fe-Mn-Si, Fe-Mn-Si-RE and Fe-Mn-Si-Cr shape memory alloys were measured from 150 K to 600 K by using an electrostatic audio-frequency internal friction instrument. The internal friction characteristics of the antiferromagnetie transition and γ→εmartensitic transformation as well as the interaction between these two transitions have been investigated. The results show that theγ→εmartensitic Lransformation is partly restrained, but can still continue below the Neel temperature (Tγ). When the temperature TN is slighdy below the Ms temperature, the internal friction peak associaled with the paramagnetic → antiferromagnetic transition disappears upon cooling due to the occurrence of the γ→ε martensitic transformation, and only the mteal friction peak associated with the γ→ε martensitic transformation can be observed. When the Neel temperature (Tγ) is much helow the temperature Ms, the internal friction peaks appear near Tγ and Ms respectively upon cooling. The rare earth elements reduce the Tv and raise the temperature Tγ, thus in Fe-Mn-Si-RE, the amount of the martensitic phaseεincases and two internal friction peaks appear near temperatures Tγ and Tγ respectively upon heating.