Abstract: The long-term use of antibiotics in clinical practice leads to bacterial variation and resistance. In addition, the excessive or improper use of antibiotics in medical and agricultural fields increases the occurrence of bacterial resistance. In 2017, the World Health Organization has for the first time released a list of 12 bacteria or bacterial families that pose the greatest threat to human health and for which new antibiotics are desperately needed, and three quarters of them are Gram-negative bacteria. Gram-negative bacteria has multi-layered cell wall that prevents many antibiotics from accessing their targets. Therefore, it is very difficult to develop drugs against Gram-negative bacteria, no new class of antibiotic has been approved for Gram-negative pathogens in over fifty years. Here, we summarized recent advances in the study of new antibacterial agents with different mechanisms of action against Gram-negative pathogens.