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In this work,a series of molecular dynamics simulations have been carried out to investigate the structure and dynamics properties of protic ionic liquid(IL)ethylammonium nitrate(EAN)at various temperatures.Our simulation results showed that the temperature has a considerable influence on the dynamics properties of EAN rather than its structure properties.Increasing temperature can significantly accelerate the translational and rotrational motions of cations and anions.We found that the ion-pair lifetime of protic EAN can be up to several nanoseconds at 300 K and the corresponding structural relaxation time can reach up to several tens of nanoseconds,which are one order of magnitude greater than the counterparts of aprotic IL [bmim][PF6] in the previous work.[2] Such differences can be attributed to the stronger hydrogen bonds(HBs)between cations and anions in protic ILs.By comparison,we found that both the lifetime and structural relaxation time of HBs in protic EAN are obviously longer than those in aprotic [bmim][PF6],especially for the HB structural relaxation time of protic EAN also up to several nanoseconds at 300 K,which can be comparable with the ion-pair lifetime.Our simulations reveal clearly that the HBs play a more important role in determing the dynamics properties of protic ILs compared to the aprotic ILs.