Abstract: Objective：To detect whether HENOS we cloned could be expressed in mouse lung after intratracheal administration of recombinant adenovirus vector. Methods：HENOS cDNA were obtained by RT-PCR from total RNA which extracted from human HUVEC. The replication-deficient heNOS recombinant adenovirus vector was constructed with a ligation method in vitro. The high titer of recombinant adenovirus was obtained by chromatographic methods. The expression of HENOS protein was determined by immunohistochemistry staining after intratracheal administration of recombinant adenovirus. Results：Sequence confirmed the cloned cDNA containing the whole ORF and the HENOS cDNA was about 3731bp in size.It showed 99.93% identity with that of HENOS cDNA in GenBank（*163729）.The biological activity of HENOS protein was examined in transfected cos7 cell line with HENOS cDNA in eukaryotic expression vector of pcDNA3.0. The replication-deficient recombinant adenovirus vector containing HENOS cDNA was constructed successfully and the purified viral titer was 2.0×1010pfu/ml. After intratracheal administration of the recombinant adenovirus, HENOS expression was detected in the majority of bronchial epithelium, alveolar lining cells, endothelial cells and smooth muscle cells of pulmonary vessels. In control, little endogenous eNOS immunoreactivity was detected in pulmonary vessels and it was no eNOS immunoreactivity in bronchial and alveolar epithelial cells. Conclusion：The replication-deficient recombinant human endothelial nitric oxide synthase mediated by adenovirus vector constructed could be delivered into the lung tissue of mouse by intratracheal administration of recombinant adenovirus and can be expressed in lung tissue in high-efficiency.