Objective To investigate longitudinally maternal left cardiac morphologic and functional parameters change of complicated twin pregnancies. Methods A group of 20 complicated twin pregnancies who was diagnosed by regular prenatal examinations was obtained as study group for analysis and 50 normal twin pregnancies were selected as control group. These cases underwent serial fetal ultrasound examinations and maternal echocardiography at 11~14 weeks，21~26 weeks and 28~34 weeks of gestation examined and delivered in Beijing Obstetrics and Gynecology Hospital. Left cardiac morphologic and functional parameters were assessed longitudinally in complicated twin pregnancies who developed pre-eclampsia and fetal growth restriction，and compared with normal twin pregnancies.Results Maternal left atrial end-diastolic dimensions showed significant increase throughout the pregnancy period in both two groups，left atrial end-systolic dimensions showed significant increase in study group，especially between second- and thrid- trimester. Compared with control group，left ventricular end-systolic dimensions was higher and at 11~14 weeks， the difference was statistically significant(P＜0.05)；Peak velocity of Early diastolic period/peak velocity of early diastolic filling (E/e'') showed significant increase throughout the pregnancy period in both two groups，but cardiac output（CO），cardiac index（CI），heart rate（HR）and left ventricular ejection fractions（LVEF）remained stable throughout the pregnancy period in study group; Compared with control group，LVEF was lower at 11~14 weeks，and Tei index was higher at 21~26 weeks in study group, the difference was statistically significant between two groups(P＜0.05).Conclusion Left atrial end-systolic and end-diastolic dimensions showed significant increase in complicated twin pregnancies，but CO，CI，HR and LVEF does not undergo the profound adaptable longitudinal changes that occur in normal twin pregnancies，left ventricular end-systolic dimensions was higher and LVEF was lower at early second-trimester，and overall cardiac function was poor at second-trimester.