Abstract: Objective To explore the correlation between fetal soft ultrasound markers and chromosomal copy number variation (CNV), so as to provide experimental evidence for prenatal diagnosis using fetal soft ultrasound markers. Methods A total of 580 single pregnant women who admitted to Xuzhou Maternal and Child Health care Hospital from December 2019 to December 2021 were enrolled. They underwent ultrasound examination and showed soft indicators of fetal ultrasound without obvious ultrasonic structural abnormalities. The amniotic fluid was extracted for chromosomal microarray analysis (CMA).According to the number of soft indexes, the pregnant women were divided into two groups: a single ultrasonic soft index group (n=486) and a two or more ultrasonic soft index group (n=94).Then, according to different types, the single ultrasonic soft index group was subdivided into 10 subgroups and the incidence of CNV in each group and among each subgroup was compared. Results The overall incidence of chromosomal CNV in 580 samples was 13.4% (78/580). The incidence of chromosomal CNV in the two or more soft ultrasound index group was 31.9% (30/94), which was significantly higher than that in the single soft ultrasound marker group (9.9%,48/486), with statistical difference (P<0.001). The subgroup with a higher chromosome CNV detection rate was: nasal bone deletion/incomplete ossification (17.3%,18/104), and cervical transparent layer (NT) thickening/posterior cervical skin folds (NF) (13.2%,14/106). Conclusions In prenatal counseling, CMA is recommended for invasive prenatal diagnosis in pregnancy women with two or more soft ultrasound marker and single soft ultrasound marker, such as nasal bone loss/incomplete ossification and NT/NF thickening.