Long non-coding RNA (lncRNA) Ewing sarcoma associated transcript 1 (EWSAT1) has been identified as an oncogene, and its dysregulation is closed corrected with tumor progression in Ewing sarcoma. Recently, high-through put analysis reveals that EWSAT1 is also highly expressed in human nasopharyngeal carcinoma (NPC). However, whether the aberrant expression of EWSAT1 in NPC is corrected with malignancy or prognosis has not been expounded. Herein, we identified that EWSAT1 was up-regulated in NPC tissues and cell lines, and higher expression of EWSAT1 resulted in a markedly poorer survival time. EWSAT1 over-expression facilitated, while EWSAT1 silencing impaired cell growth in NPC. In addition, mechanistic analysis demonstrated that EWSAT1 up-regulated the expression of miR-326/330-5p clusters targeted gene cyclin D1 through acting as a competitive ‘sponge’ of miR-326/330-5p clusters. Collectively, our data revealed that EWSAT1 promotes NPC cell growth in vitro through up-regulating cyclin D1 partially via ‘spongeing’ miR-326/330-5p clusters.