목적: The discovery of fetal nucleic acids in the plasma of pregnant women has led to the development of noninvasive prenatal testing (NIPT). The objective of this study was to discover a panel of placental miRNAs as potential novel biomarkers for NIPT of fetal T21 and to predict the biological functions of new biomarkers using bioinformatics tools. 방법: Using microarray-based genome-wide expression profiling, we compared the expression levels of miRNAs in whole blood samples from non-pregnant women, whole blood samples from pregnant women, and fetal placenta samples from pregnant women with euploid or T21 fetuses. We analyzed the differentially expressed miRNAs according to the presence or absence of disease and tissue type (p value <0.05 and two-fold expression change). Potential target genes of miRNAs were predicted using the miRBase program. To predict their functions, the functional annotation tools provided by the WebGestalt database were used. 결과: We identified 299 miRNAs which reasonably separate the whole blood from the placenta. Among the identified miRNAs, 150 miRNAs were up-regulated in the placenta, and 149 miRNAs were down-regulated. Most of the up-regulated miRNAs in the placenta were members of the mir-498, mir-379, and mir-127 clusters as placenta specific miRNA located on hsa19 and hsa14. Among the up-regulated miRNAs in the placenta, mir-1973 and mir-3196 were expressed at higher levels in the T21 placenta than in the euploid placenta. The two miRNAs potentially regulate 203 target genes that are involved in developmentof brain, central nervous system, and nervous system. Interestingly, the genes are significantly associated with T21-related disorder such as congenital abnormalities, mental disorders, and nervous system diseases. 결론: Our study indicates placenta-specific miRNAs that may be potential biomarkers for NIPT of fetal T21 and provides new insights into the molecular mechanisms of T21 via regulation of miRNAs.