There have been several evidences that the mRNA expressions in the peripheral leukocytes may indicate not only physical but also psychological states. The purpose of this study is whether the mRNA expressional changes in the leukocytes are related to the mental states across the menstrual cycle in reproductive healthy female subjects. Thirty-eight female subjects (22.4+/-1.4 year-old) were participated in this study at three menstruation cycle periods (menstrual, follicular and luteal phase). The FKBP5 (FK506-binding protein gene), SERT (serotonin transporter gene) and COMT (catechol-o-methyltransferase gene) mRNA expressions in the leukocytes were determined with hormonal data. The psychological changes were assessed with self-rating hospital anxiety and depression scale (HADS). Only one thirds of subjects (n=12) had regular menstrual cycles during the experiment. So we analyzed the data from these 12 subjects. The anxiety score of each subject was changed across the menstrual cycle (Friedman test: P<0.05). The FKBP5 mRNA expression was significantly lower in the follicular phase than in the other phases but no changes were seen in either SERT or COMT mRNA expressions among the phases. In conclusion, there are differences of HADS anxiety score and FKBP5 mRNA expression in the leukocytes across the menstrual cycle but there is no correlation between anxiety scores and FKBP5 mRNA.