Umbilical cord blood hematopoietic stem cells (UCB HSCs) transplantation has attracted the attention of many researchers due to the low probability of GVHD and HLA mismatching; however, the use of this resource for adults has been limited due to the inadequate number of CD34 + HSC from any individual donor. Recent reports indicate that circular RNAs (circRNAs) are involved in stem cell properties. In this study, the functional role of several candidate circRNAs, including circCORO1C and circBIRC6 in CD34 + HSCs was investigated. The results showed that the expression levels of circBIRC6 and circCORO1C and simultaneously, the expression of transcription factors such as NANOG and SOX2 were significantly downregulated during differentiation. Taken together, these findings suggested that circBIRC6 and circCORO1C were involved in the process of self-renewal of CD34 + HSCs, and their expression is downregulated by differentiating these cells.