The estrogen-related receptor (ERR) is a member of nuclear receptors (NRs) superfamily that play a central role in diverse biological processes including energy metabolism,reproduction and development.In this study, the ERR gene was cloned from ovary of the swimming crab, Portunus trituberculatus, by 3 and 5 RACE procedures. The full-length cDNA of ERR was 2681bp including 1284bp open reading frame (ORF) that encoded 428 amino acids (aa) and the predicted protein contained the typical structural features of the known NRs proteins.