Aims To construct an expression vector of human lncRNA H 1 9 ,and to determine the effect of H1 9 overexpression on MCF-7 cell proliferation. Methods Total RNA was extracted from MCF-7 cells,and the full-length of H1 9 lncRNA was amplified by RT-PCR and subcloned into pcDNA3.1 (-)ex-pression vector.The constructed H1 9 expression vector was transfected into HEK-293T and COS-7 cells and the H1 9 lncRNA expression was evaluated by real-time PCR.Following the transfection of H1 9 expression vec-tor into MCF-7 cells for 0,24h and 48h and H1 9 siR-NA interference fragment into MCF-7 cells for 24h, MCF-7 cell proliferation was determined by MTS as-say.Results A hH1 9-pcDNA3.1 (-)expression vector was successfully constructed. At Forty-eight hours after the transfection with H1 9 expression vector in to MCF-7 cells,cell proliferation was significantly increased in the transfected group compared to those without transfection and to those transfected with a neg-ative control vector,while twenty-four hours after the transfection with H1 9 siRNA interference fragment into MCF-7 cells,cell proliferation was significantly de-creased in the transfected group compared to those transfected with a negative control vector.Conclusion Ectopic overexpression of H1 9 lncRNA can promote breast cancer MCF-7 cell proliferation.