Chloroquine is an anti-malaria agent. This study is designed to evaluate inter-ethnic differences of therapeutic effect of chloroquine and search the cause of these ethnic differences. For this purpose, chloroquine will be administered to four ethic groups of Korean, Caucasian, African and Southeast Asian and chloroquine concentration in blood will be measured. The result of this study will be helpful in finding more adequate dosing regimen of chloroquine in patients with malaria.

Inclusion Criteria:

• aged 20 - 50 male subjects (6 Koreans, 6 Caucasians, 6 Africans and 6 Southeast Asians)
• Subjects with body weight ≥ 45 kg and within ±20% of the ideal body weight : Ideal body weight = (height [cm] - 100)x0.9.

Exclusion Criteria:

• Subjects who have drunken habitually (exceeding 21 units/week, 1 unit = 10 g of pure alcohol) or who are unable to abstain from drinking during the study period from 2 days prior to the first administration of investigational product and during this study.
• Subjects deemed ineligible by investigator based on other reasons, including abnormal laboratory values or diseases.