Abstract: Many sequencing technologies have been used in molecular biology research and clinical practice. In 1977, Sanger Sequencing （the first generation DNA sequencing technology） was firstly introduced. With the development of sequencing technology in the past 30 years, the next generation sequencing （NGS） was also used, and the third generation sequencing technology based on the single DNA molecule was developed. These sequencing technologies are benefit for the development of noninvasive prenatal screening（NIPS）. Compared with those traditional technologies combined with amniocentesis and chorionic villus sampling，NGS obtains the fetal chromosomal information from sequencing cell-free fetal DNA （ｃｆｆＤＮＡ） ｉn maternal plasma, which avoids the fetal risk during the sampling procedure. Researchers found that the massively parallel sequencing （MPS）-based test was of high sensitivity and specificity in detecting fetal trisomies 21 and 18. The clinical application statement and the committee opinion were published by many health organizations. In 2013, the single cell sequencing（SNS） has also been used in the clinical trials of prenatal assisted reproductive technology. The live birth rate of in vitro fertilization and embryo transfer（IVF-ET） could be significantly improved in future using the single oocyte sequencing. So, the NGS will be widely used in the prenatal diagnosis.

Key words: Down syndrome, Prenatal diagnosis, DNA, Sequence analysis