Maltose　transporter　is　an　important　kind　of　transmembrane　transporters　with　significant　biological　functions　which　bears　the　transportation　of　intracellular　and　extracellular　maltose　molecules.　The　transport　process　of　maltose　molecule　accompanies　with　large　scale　cooperative　motions　between　different　domains　of　maltose　transporter.　And　these　motions　involve　some　key　residues　that　mediate　signal　transduction　and　allosteric　effects　between　different　regions　of　the　protein.　In　this　study,　we　identified　the　key　residues　in　this　protein　system　with　the　thermodynamic　method　based　on　the　elastic　network　model　which　was　developed　by　our　group.　On　this　basis,　we　explored　the　long-range　synergies　within　the　maltose　transporter.　These　results　are　helpful　to　a　better　understanding　the　molecular　mechanisms　of　function　of　transporters.