Polymeric immunoglobulin receptor (pIgR) is a key immune factor, medicating the transport of polymeric immunoglobulins (pIg) through the epithelial cells into the mucosal secretions to protect the organisms from was first cloned and sequenced by pIgR contained 1 584 nucleotides, 3’UTR, 5’UTR, and an open reading frame (ORF) of 1 005 nucleotides that encoded for a polypeptide of 334 amino acid. Gene homology comparisons showed that Takifugu rubripes, indicating a high conservation of gene. Multiple sequence alignment demonstrated the pIgR of teleosts was composed of two Ig-like domains (ILDs), corresponding to the ILD1 and ILD5 of Mammal’s pIgR. The phylogenetic tree sequences of . Expression analysis revealed that pIgR gene was expressed in almost all tissues of healthy s, with higher levels in the mucosa-associated lymphoid tissues. were evaluated following bath immunization by real-time PCR, and the results showed that the relative expression amount increased firstly and then decreased within 72 h in all the tested tissues, and reached its maximum expression within 48 h and the appeared earliermucosa-associated. These results suggested pIgR played a critical role in the mucosal immunity of teleost.