목적: The aim of this study was to evaluate the relation between different fasting glucose level determined by oral glucose tolerance test (OGTT) and maternal and perinatal outcomes in gestational diabetes mellitus (GDM) patinets 방법: We reviewed the medical records of 753 pregnant women who had 3hour-100g OGTT between March 2001 and April 2013. Among them, 275 patients were diagnosed GDM and we divided two groups according to fasting glucose levels. 155 patients had normal fasting glucose value (<95 mg/dl) and 120 patients had abnormal fasting glucose value (≥95 mg/dl). Therefore, we compared maternal and perinatal outcomes between two groups. 결과: Maternal body weight before and after pregnancy and maternal weight gain were statistically significant between two groups (p<0.001). In addition, there were significantly differences in BMI of prepregnancy and delivery time (p<0.001). In addition, cesarean section rate were 56.7% (88/155) and 72.5% (87/120) in normal and abnormal fasting glucose group, respectively (p=0.001). Women who had abnormal fasting glucose value were at significant higher risk of large for gestational age fetus (p<0.001). 결론: Maternal and perinatal outcomes could be different in women presented normal and abnormal fasting glucose value in GDM patients.