Objective To explore the value of prenatal ultrasound in diagnosis of fetal partial agenesis of corpus callosum. Methods 15 fetuses diagnosed as partial agenesis of corpus callosum by prenatal ultrasound combined with magnetic resonance imaging (MRI) were collected. Results of examination after birth or induction of labor were compared to analyze the characteristics of prenatal ultrasound. Results Direct signs were observed in the prenatal sonographic features: 12 cases (12/15, 80.0%) were missing corresponding parts in the midsagittal section of corpus callosum. Indirect signs: transparent partition morphological abnormalities (80.0%), lateral ventricle expansion (73.3%), separation of longitudinal crack on the brain pool(73.3%), posterior thalamic midline cystic mass (26.7%), “teardrop change” of the lateral ventricle (26.7%), abnormal course of pericallosal artery (26.7%), with intracranial and other system deformity in 6 cases, including multiple anomalies. Compared with the follow-up results after birth or induction of labor, the diagnostic accuracy was 80.0% of prenatal ultrasound and 93.3% of prenatal MRI. Conclusion Ultrasonography may diagnose fetal partial agenesis of corpus callosum properly, and more accurate diagnosis could be finished combining with prenatal fetal cranial MRI.