Long noncoding RNAs (lncRNAs) are the recently added players in the regulatory circuitry complex that controls the self-renewal and differentiation of human Embryonic Stem cells (hESCs).Here, we identify that GAS5 (growth arrest-specific transcript 5), a tumor suppressor and growth arrest gene which is abundantly expressed in the cytoplasm of hESCs, accelerates the G1/S phase transition and promotes stemness of hESCs by acting as a competing endogenous RNA (ceRNA).