The late stages of the HIV-1 replication cycle are important to the overall replication cycle.  During the late stages, HIV-1 replication undergoes the processes of assembly, release, and maturation, resulting in the production of a mature virus particle capable of infecting a new target cell.  The structural protein Gag and its related gene (protein) play a central role in these pathways.  The different regions of Gag worked in   concert to drive production of a mature infectious particle through protein-protein, protein-RNA and protein-lipid interactions.  The designed drug aimed directly at these stages can efficiently block the maturation and infectivity of HIV-1.  In this article, the role of structural protein Gag and related gene (protein) in late stages of the HIV-1 replication cycle and related inhibitors is reviewed.