Erythropoietin receptor (EpoR) dimerization is an important step in erythrocyte formation. Its transmembrane domain (TMD) and juxta-membrane (JM) region are essential for signal transduction across the membrane. A construct compassing residues S212-P259 and containing the TMD and JM region of the human EpoR was purified and reconstituted in detergent micelles. Solution structure of the construct was determined in dodecylphosphocholine (DPC) micelles using solution NMR spectroscopy. Our structural and dynamic studies demonstrated that the TMD and JM region is an α-helix in DPC micelles, while residues from S212 to D224 at the N-terminus of the construct are not structured. The JM region is a helix that contains a hydrophobic patch formed by conserved hydrophobic residues including L253, I257 and W258. NOE analysis, fluorescence spectroscopy and paramagnetic relaxation enhancement experiment suggested that the JM region is exposed to the solvent. The TMD and JM region of mouse EpoR had similar structures to those of the human EpoR.