Human immunodeficiency viruses HIV-1 and HIV-2 are the results of multi-interspecies transmissions from simian virus to humans. HIV-1 viruses are very divergent and are classified in three groups: M, N and O. The group M is subdivided in nine subtypes and numerous Circulating Recombinant Forms. In 1996, protease inhibitors and HAART disposal have modified the prognostic of the HIV infection. However, one of the major problems is the emergence of antiretroviral resistance. A major advance from the last year is the access to antiretroviral in resources limited countries. On the other hand, the development of a vaccine is today hypothetic.