Adverse drug reactions (ADRs) is a hypersensitivity reactions to specific medications, and remain a common and major problem in healthcare. ADRs suchc as drug-induced liver injury and life-threatening severe cutaneous adverse drug reactions including Stevens-Johnson syndrome, toxic epidermal necrolysis, and drug rash with eosinophilia and systemic symptoms can be occurred by uncontrolled expansion of oligoclonal T cells according to genetically predisposing HLA. In this review, I summarized the alleles of HLA genes which have been proposed to have association with ADRs caused by different drugs.