Ethylene plays versatile functions in regulating plant physiology. Although the high affinity ethylene receptor and its downstream regulators have been identified, the molecular recognition of the receptor interacting domains remains to be established. It has been speculated that the cytoplasmic signaling of the ethylene receptor is a two-component regulatory system involving the conserved receiver domain (RD). Here, we report the NMR chemical shift assignments for RD from Arabidopsis thaliana ethylene receptor ETR1. Nearly complete backbone and side-chain assignments were achieved at pH 6.0 and 25 °C. The assignments and backbone dynamics revealed the secondary structure and showed that ETR1-RD is a monomer in solution. These results will make it possible to monitor downstream binding partners and elucidates our understanding of phosphotransfer in the plant two-component regulatory system in the ethylene signaling pathway.