Human neural progenitor cells promise to be the source for cell therapy of variety of human neurological diseases and trauma. But the proliferation of these cells in vitro is severely limited. Via lentiviral-mediated introduction of telomerase reverse transcriptase gene (hTERT) into the cells of primary culture of human embryonic neural stem cells (NSC) we obtained the culture with extended proliferative potential. Under the conditions of low oxygen (3%) original cells ceased to proliferate after 42 population doublings (PD), NSC-hTERT cells achieve the level of 78 PD for 430 days and are proliferating further with constant rate. The culture of NSC-hTERT contains as differentiated cells (-IIItubulin or GFAP-positive) as well the nondifferentiated (most cells are nestin-positive) ones. Only a small portion of cells expresses high level of hTERT-protein. The culture can grow as monolayer (in the presence of 2% of serum) or as floating spheres (without serum). The cells preserve diploid karyotype. They have ability to form two kinds of colonies under conditions of low density. One type with usual for NSC structure contains different cell types. Cells of other colonies resemble the senesced ones with flattened shape. This study confirms that telomerized cells can be a valuable source for research and clinical application.