To improve the mechanical properties and recyclability of ethylene propylene diene monomer (EPDM), citraconated EPDM (CCA-g-EPDM) was prepared from the free radical melt grafting of citraconic acid onto EPDM, and a series of aminio acids treated CCA-g-EPDMs (CCA-g-EPDM/2-Am, CCA-g-EPDM/6-Am, CCA-g-EPDM/7-Am and CCA-g-EPDM/12-Am, where the numbers indicate the number of carbon atoms in amino acids) was made by reacting various amino acids containing different chain lengthg with CCA-g-EPDM, and then a series of ionic thermoplastic elastomers (Ionomers: CCA-g-EPDM/Am/Io) were prepared by melt mixing of CCA-g-EPDM/Am with ZnO/Zn stearate. The properties of pristine EPDM, CCA-g-EPDM, CCA-g-EPDM/Am, and CCA-g-EPDM/Am/Io were compared. The specific gravity, tensile strength, elongation at break, 100 and 200% modulus, and tear strength were mostly increased in the order, CCA-g-EPDM/Am/Io ionomer materials> CCA-g-EPDM/Am materials> CCA-g-EPDM> pristine EPDM, whereas the compression set was in the opposite order. Among the ionomers, the CCA-g-EPDM/7-Am/Io was found to be exhibited the highest mechanical properties. This ionomer had no significant change in mechanical properties and compression set with successive recycling, indicating good recyclability. These results suggest that the recyclable ionomers CCA-g-EPDM/7-Am/Io prepared in this study have high potential as new high performance thermoplastic elastomers.