Objective To observe the relationship between electrocardiogram(ECG) and pregnancy outcomes of the second pregnant women. Methods Pregnant women were divided into two groups by parity history: the second pregnancy group and the Primipara group. The incidence of abnormal electrocardiogram was recorded, then the pregnancy outcome including the delivery mode and the premature birth rate were followed up. Results The incidence of abnormal ECG in the second pregnancy group was significantly higher than that in primipara group(P<0.05) and the incidences of Nodal tachycardia, Premature ventricular contraction, ST-T changes in the group of the second pregnancy were higher than that in the group of Primipara (P<0.05). The incidence of cesarean delivery and premature birth in the second pregnancy group with abnormal ECG group was significantly higher than that in pregnant women with normal ECG group (P<0.05). Conclusion The second pregnant women are more likely to have ECG abnormality, the pregnant women with abnormal ECG are easily suffer from cesarean delivery and premature birth.