The aim of this study was to observe the relationships between the amount of menstrual blood loss (MBL) and age, parity, number of pregnancy and induced abortion, and the iron nutriture in married Korean women. Fifty-one healthy women aged 26 to 48 years were tested for their MBL, hemoglobin(Hb) concentration, hematocrit (Hct) value, mean corpuscular hemoglobin concentration (MCHC), serum iron and ferritin concentrations. The results of this study are summarized as follows : 1) The mean value and standard error of mean of the MBL was $32.0{pm}3.94ml$, and the range of MBL was 3.8-127.2 ml for total subjects. Maximum number (23.5%) of the subjects fell in the group with MBL of 10-l9ml, while 17.7% showed MBL above 50m1. 2) There were no statistically significant differences on the mean amount of MBL between the age groups 25-48 years. 3) The mean amount of MBL in 1-2 and 3-4 para groups were 28.5 and 36.1 ml, respectively, but the difference between two groups was not significant 4) It was observed that the mean amount of MBL was gradually decreased as the number of pregnancy and induced abortion were increased, but the significance was not observed. 5) The mean values of Hb concentration, MCHC and serum iron concentration were slightly decreased in subjects with MBL of more than 50ml but the statistical significance was not observed. The mean of Hct value was not influenced by the amount of MBL. While serum ferritin concentrations were markedly decreased and the prevalence rate of anemia was markedly increased as the amount of MBL was increased. There was significant difference (P<0.05) between the mean amount of MBL with respect to the serum ferritin concentration.