The human immunodeficiency viruses(HIV) cause the destruction of CD4 lymphocytes, resulting in the development of acquired immunodeficiency syndrome (AIDS). The entry of HIV into host cells is mainly mediated by the fusion of the viral and cellular membranes, which involves the interactions of a series of biomacromolecules, such as gp120，gp41，CD4 and CCR5. The deep understanding of the crystal structures, the surfactant details of their interaction, and the change of conformation during interaction of the macromolecules provides a new idea for the anti HIV drugs. At present some new drugs have been found arising from this idea.