Abstract: Quorum sensing (QS) is a cell-density-dependent method for information transmission among bacteria, as well as a mechanism for the bacteria to adapt to environment. LuxR family protein plays a key role in gram-negative bacterial QS system as a kind of transcription regulators and participates in a variety of biological behaviors with LuxI protein and signal molecules, such as bioluminescence, biofilm formation, virulence factors production, and so on. The advances in the research of LuxR family protein in QS system of gram-negative bacteria were summarized in this review.