Objective To explore the clinical significance of absent nasal bone at 11-13+6 weeks of pregnancy combined with nuchal translucency screening in prenatal diagnosis of fetal chromosomal abnormalities. Methods 225 cases of 11-13+6 weeks’ singleton pregnancy were retrospectively analyzed, all were found absence of nasal bone by ultrasound screening. Two groups were divided according to the normality of nuchal translucency. Group A, the one with thickened nuchal translucency. Whereas group B, the one with normal nuchal translucency. The detection rate of the chromosomal abnormality between the group A and group B were analyzed to show if there is a statistic difference. Result There were 51 cases(22.67%,51/225) with absent nasal bone with thickened nuchal translucency (≥3mm), 174 cases(77.33%,51/225) with absent nasal bone with normal nuchal translucency (＜3mm). A total of 59 cases with chromosomal abnormalities were detected among 225 fetuses (26.22%,59/225), 54 cases with aneuploidy (24.00%, 54/225) and 5 cases with other chromosomal abnormalities. A total of 15 cases by chromosomal microarray analysis , and 2 cases presented chromosomal abnormalities. 36 cases with chromosomal abnormalities were detected in group A（70.59%,36/51）,including 23 cases with trisomy 21 (45.10%,23/51), 10 with trisomy 18 (19.61%,10/51), 1 with trisomy 13 ,1 with 45,X and 1 with chromosome deletion (1.96%，1/51). 23 cases with chromosomal abnormalities were detected in group B（13.22%,23/174）,including 12 with trisomy 21 (6.90%，12/174), 5 with trisomy 18 (2.88%,5/174), 1 with trisomy 13 and 1 with 47，XYY (0.57%, 1/174)，4 with chromosome polymorphism (2.30%, 4/174). The detection rate of aneuploidy in group A was significantly higher than that in group B(χ2=67.098,P＜0.001). The detection rate of trisomy 21 and trisomy 18 in group A was significantly higher than that in group B(χ2=43.817, 17.750，P＜0.001, 0.001). There were significant differences between two groups. Conclusion As a noninvasive imaging examination, absent nasal bone combined with nuchal translucency screening at early pregnancy can indicate the chromosomal abnormalities earlier, especially trisomy 21 and trisomy 18. Chromosomal microarray analysis can revealed specific abnormal chromosomal fragments and pathogenic genes for normal fetal chromosomes.