In this work,the interactions between transthyretin(TTR) and one brominated flame retardant(BFR) and two hydroxylated BFRs,namely 3,5,3′,5′ tetrabromo 4,4′ dihydroxydiphenylsulfon(TBS),4 hydroxy 2,2′,3,4′,5,5′,6 heptabromodiphenyl ether (4 OH-BDE-187) and 6 hydroxy 2,2′,3,4,4′,5,5′ heptabromodiphenyl ether(6 OH-BDE-180),were studied by native electrospray ionization mass spectrometry(Native ESI-MS) and molecular docking simulation(MDS).ESI-MS results indicated that,in a 37 ℃ physiological pH value buffer,TBS,4 OH-BDE-187 and 6 OH-BDE-180 could stably combine with TTR by the stoichiometric ratios of 1∶1,1∶1 and 2∶1 to form TTR complexes,respectively.Molecular docking simulation was performed to generate the models of the protein complexes formed by these three ligands binding toTTR.MDS results demonstrated that the binding sites of TTR with these three ligands may be in the pocket around ASP 74 residue.The study is helpful for understanding the toxicology mechanisms of brominated flame retardants and their hydroxylated metabolites.