More than 25 years have passed since HIV was identified as a causative agent of AIDS. In the monotherapy era, the efficacy of antiretroviral therapy was limited due to emergence of drug resistance. In late 1990s when the highly active antiretroviral therapy (HAART) was started to apply, the mortality of HIV infected people dramatically declined. Nowadays, more than 20 drugs are applicable and treatment regimen has become more potent and more convenient. However, emergence of multi-drug resistant HIV and long-term toxicity of antiretroviral is still remarkable concern. Raltegravir, the first approved integrase inhibitor (INI), shows preferable safety profile. When long-term reliability of INI is proven, antiretroviral combination will be individualized by choosing the optimal drug from 4 classes.