OBJECTIVES: Findings from behavioral genetics which demonstrate the high heritability of personality traits have stimulated the search for the specific genes underlying personality. A large number of association studies have investigated a correlation between serotonin transporter-linked promoter region(5-HTTLPR) polymorphism and personality traits but the results have been inconsistent. So, the aim of this study is to investigate in a large sample with homogenous background about ethnicity, gender, occupation, and age. METHODS: The participants included 247 healthy Korean female adults(mean age=23.12, SD=3.22)with no history of psychiatric disorders and other physical illnesses. Genomic DNA was extracted from peripheral blood, and genotyping was performed by PCR. Personality assessment was done with the Temperament and Character Inventory(TCI). RESULTS: Genotype Frequencies are l/l 3.6%, l/s 32.8% and s/s 63.6%(l allele: 20%, s allele: 80%). This low frequency of the l allele and l/l genotype was different from Caucasian results. No significant association was observed between 5-HTTLPR polymorphism and personality traits in a Korean female population. CONCLUSIONS: This study investigated the association between 5-HTTLPR polymorphism and personality traits in Korean female subjects, a large sample with homogeneous background about ethnicity, gender, occupation, and age. No significant association was observed between 5-HTTLPR polymorphism and personality traits in a Korean female population.