Purpose: Although Saliva provided with various defense mechanisms, such as the buffering and the antioxidant defense systems, there is little information concerning the changes which occur in salivary defense system in response to exercise in the follicular (low temperature) and luteal (high temperature) phases of the menstrual cycle. Therefore, we investigated that the effects of the menstrual cycle on markers of salivary buffering action and oxidation-reduction status after moderate exercise. Methods: Seven healthy females completed the exercise by bicycle ergo-meter of 50% HR reserve (50％HRR) for 30 min during the follicular and luteal phases in the enstrual cycle. Saliva samples were collected before, immediately, and 30 and 60 min after exercise, and the buffering capacity (sBC) and oxidation-reduction potential (sORP) of whole saliva are determined. Results: The sBC increased immediately and 30 min after exercise compared with that of before exercise, but spH was practically unchanged. The correlation coefficient between the increment of sBC from before exercise and the increment of blood lactate concentration was 0.383(p=0.0786). While the sORP decreased immediately, 30 and 60 min after exercise compared with that of before exercise. The sPO decreased 30 and 60 min after exercise compared with that of immediately after exercise and the salivary uric acid concentration in follicular phase at 30 min after exercise was higher than that of luteal phase. The decrement of sORP from before exercise is a good correlated with the changes of salivary uric acid concentration (r=0.632, p<0.001). Conclusion: These results suggest that moderate exercise during the follicular (low temperature) and luteal (high temperature) phases of the menstrual cycle did not influence the sBC and the sORP, however, the salivary antioxidant, such as salivary uric acid, may be influenced during exercise between menstrual cycle phases.