Purpose: The objective of this study was to investigate the prevalence of antenatal depression in pregnant women and its influencing factors. Methods: With a cross-sectional survey design, a total of 396 pregnant women were recruited from a local obstetrics and gynecology clinic. Measurements included antenatal depression, perceived stress, predictors of depression during pregnancy, and demographic and obstetric characteristics. Results: Mean antenatal depression score was 8.20 (standard deviation=4.95) out of 30, falling into its normal range. However, the prevalence of antenatal depression was 35.9% when cut-point of 9/10 was used. The prevalence of antenatal depression among women in the first trimester was 31.4%. It was slightly increased to 34.9% in the second trimester but significantly increased to 40.5% in the third trimester. In multiple logistic regression analysis, experiencing prenatal anxiety (odds ratio [OR], 4.16), having no job (OR, 2.90), lower self-esteem (OR, 1.62), and higher perceived stress (OR, 1.32) were significant factors influencing antenatal depression. Conclusion: Negative feeling such as feeling anxious, lower self-esteem, and higher perceived stress during pregnancy are key factors affecting antenatal depression. Thus, antenatal nursing intervention focusing on pregnant women's feeling upon their job status is necessary to improve their antenatal psychological well-being.