Abstract: Objective To explore the clinical value of non-invasive prenatal gene detection in prenatal screening for fetal chromosome aneuploidy.Methods 900 single pregnant women who were tested for noninvasive prenatal gene in our hospital from January 2017 to March 2018 were selected as the subjects. The peripheral venous blood of pregnant women was collected and DNA was free, and the high flux was sequenced. High risk parturients were examined by amniotic cavity or umbilical vein puncture and karyotype detection.Results Among 900 single pregnant women, 11 cases were detected with high risk by testing peripheral blood, and the positive rate was 1.22%. Among them, 7 cases were 21-trisomy syndrome, 1 case was 13-trisomy syndrome, and 3 cases were 18-trisomy syndrome. The chromosomal karyotype analysis of 11 high-risk pregnant women screened by noninvasive prenatal gene detection showed that the coincidence rate of noninvasive prenatal gene detection and chromosome karyotype analysis was 100%. High risk pregnant women had the followingindicators of noninvasive detection:elder age, NT thickening, Down syndrome. The karyotype of 21-trisomy syndrome was (47, XN, + 21), the chromosome karyotype of 13-trisomy syndrome was (47, XXX), the karyotype of 18-trisomy syndrome was (47, XN, + 18). All of the pregnant women with high risk terminated pregnancy.Conclusion Noninvasive prenatal gene detection has higher diagnostic accuracy for fetal chromosomal aneuploidy. It has the advantages of noninvasive, high sensitivity and high safety. Early screening for fetal defects has worthy of clinical value.