Abstract:Bacteria predominantly adapt to environmental changes to ensure their growth and proliferation through onecomponent，two-component and three-component regulatory systems． Conjugative pilus expression (Cpx) system is one of the two-component regulatory systems in gram-negative bacteria．It is composed of the membrane-anchored sensor kinase CpxA，the cytosolic responding regulator CpxR and the accessory protein CpxP in the periplasm． In this review，the components of the Cpx system and their structural characteristics were introduced and the latest research on Cpx signal integration was summarized．Further attempts to better understand the mechanisms were also proposed．