Abstract: Objective To screen the differentially expressed circRNAs in adult and fetal mesenchymal stem cells and explore the role and mechanism of circRNAs in regulating aging in MSCs. Methods Through bioinformatics analysis to 3 adult bone marrow-derived mesenchymal stem cell samples and 3 fetal cord blood-derived mesenchymal stem cell samples from microarray data GSE122178,the differentially expressed circRNAs were screened and its biological function and mechanism were predicted. Results Compared to adult MSCs,the expressions of 66 circRNAs in fetal MSCs were significantly up-regulated while the other 107 circRNAs were significantly down-regulated.Among them,the expression of hsa_circ_0080170 was up-regulated and the expression of hsa_circ_0060055 was down-regulated most significantly.hsa_circ_0080170 had 6 downstream miRNAs binding sites and 714 target genes;hsa_circ_0060055 had 28 downstream miRNAs binding sites and 591 target genes.KEGG analysis showed that the target genes of hsa-miR370 and hsa-miR203a were significantly enriched to 31 signal pathways such as signaling pathways regulating pluripotency of stem cells;hsa-miR1225-5p and hsa-miR197 target genes were significantly enriched to 17 signal pathways such as regulation of actin cytoskeleton. Conclusion Through the circRNAs differential expression profiles in adult and fetal mesenchymal stem cells,we have predicted that hsa_circ_0080170 and hsa_circ_0060055 may play a role in regulating the cell fate of mesenchymal stem cells with aging.