Acquired immunodeficiency syndrom (AIDS), thepandemic immunosuppressive disease of thesecond half of the 20th century, is still a threateningdisease world-wide. UNAIDS and WHO estimatedthat the number of people living with Humanimmunodeficiency virus (HIV) at the end of theyear 2001 standed at 40 million. In sub-SarahaAfrica, approximately 3.4 million new infectionsoccurred in 2001, bringing to 28.1 million the totalnumber of people living with HIV/AIDS in thisregion. The etiological agent of AIDS has beenidentified as a retrovirus of the Lentiviridae family(Barre-sonousso et al., 1983; Gallo et al., 1984).Originally referred to as HTLV-III or LAV, thisenveloped, single-stranded RNA virus is nowdesignated HIV, to eliminate confusion caused bytwo names for the same entity (Coffin et al., 1986;Gallo and Montagnier, 1988). The development ofantiretroviral therapy against AIDS has been anintense research effort since the discovery of thecausative agent.A large array of drugs and biologic substancescan inhibit HIV replication in vitro. Zidovudine hasbeen reported to decrease both mortality and thefrequency and severity of opportunistic infectionsin a select group of patients infected with HIV(Fischl et al., 1987). However, the administration ofzidovudine has also been associated with substantialtoxicity, primarily hematologic in nature (Richmanet al., 1987; Schmitt et al., 1988; Larder et al., 1989).Therefore, the development of specific and potentanti-AIDS drugs to restrain infection by HIVremains an urgent need.Numerous plant-derived substances have beenevaluated for their inhibitory effects on HIVreplication in vitro (Sun et al., 1996; Zhao et al., 1997;EI-Meselhy et al., 2000).And medicinal plants from Indonesia (Kusumotoet al, 1992), Sri Lanka (Kusumoto et al, 1995), China(Ma et al., 1998), Inner Mongolia in China (Ma etal., 2000; 2001), Panama (Lim et al., 1997) andSudan (Hussein et al., 1999) have been tested fortheir inhibitory activities on HIV-1 protease byHattori group. This paper reviews the inhibitoryeffects of Korean plants and their compoundsagainst HIV-1 protease.