Objective To evaluate the pattern of development of fetal cerebral sulei by prenatal ultrasound and its clinical significance. Methods Sixty hundred and ninety-two fetuses at age from 17 to 40 weeks were observed for the development and depth of cerebral sulci (parietal-occipital sulcus, calcarine suleus, central sulcus, eingulate sulcus, cingulate gyrus, and sylvian fissure) by transabdominal ultrasonography. Results Parietal-occipital sulcus,calcarine sulcus,and sylvian fissure were visible at about 19 weeks of gestation, central sulcus was at about 25 weeks, cingulate sulcus and cingulate gyrus were at about 26 weeks. One case of them was considered as cerebral sulei growth retardation due to the signs of invisible parietal-occipital sulcus and sylvian fissure at 24 weeks of gestation. Two cases were considered as cerebral sulci growth retardation due to the signs of invisible parietal occipital sulcus and central sulcus and the shallow blunt shape of sylvian fissure at 29 weeks of gestation. There were positive correlations between the depths of fetal cerebral sulci and gestational weeks, and negative correlations between their relative depths and gestational weeks(all P <0.05), Conclusions Transabdominal ultrasonography can be use to observe the development of fetal cerebral sulci (parietal-occipital sulcus, calcarine sulcus, central sulcus, eingulate sulcus,cingulate gyrus,and sylvian fissure). The depth of cerebral sulci is relative to gestational weeks,and would be considered for prenatal assessment of cerebral sulci maldevelopment, such as cerebral sulci growth retardation and lissencephalia.