The safety/tolerability and pharmacokinetics (PK) of Naftopidil (commercial name: Flivas) after oral administration will be investigated in Korean healthy male volunteers. All volunteers will be assigned to 2 groups and administered a lower single dose tablet (Period 1). After one week's wash-over period, the volunteers take higher dosages (Period 2).

Inclusion Criteria:

• Healthy males subjects, 20-45 years inclusive
• Weight over 55 kg inclusive and Ideal Body Weight (IBW) between -20% and +20% inclusive
• Written informed consent given

Exclusion Criteria:

• Hypersensitivity to drugs(aspirin, antibiotics and so on) including naftopidil
• History or presence of any clinically significant liver or kidney disease, gastrointestinal, cardiovascular, respiratory, endocrinal, musculoskeletal, neurologic/psychiatric, urinary, hematological, oncological pathology
• Have a history of drug abuse, or show positive for drug abuse at urine screening
• Have participated in another clinical study within 2 months prior to entering inth the study
• Are considered ineligible by the investigator due to clinical laboratory results or any other relevant reasons