Abstract： ObjectiveTo observe the effect of noradrenalin(NE) on human pulmonary arterial smooth muscle cells (PASMC) by using a proteomic approach.Methods Human PASMC were cultured primarily in vitro.Experiments were performed in the 3rd to 5th passages of the cells.The human PASMC were cultured in serum-free medium for 24 h prior to treatment with either NE (10-5 mol/L, the test group)or completed-serum culture medium (the control group) for 24 h. And then analysis via 2-DE gel electrophoresis and MALDI-TOF-MS was performed to display the different protein profiles of whole cell protein from cultures of the control and the NE-treatment group. Real-time RT-PCR and Western blot analysis were used to confirm the proteomic analysis.Results The purity of the primary culture cells was about 99％.When the human PASMC were treated by NE, the expression of different groups of cellular proteins was changed, including cell cytoskeleton-associated proteins, cell signal-associated proteins, and glycolytic and metabolism-associated proteins. The results were confirmed using real-time RT-PCR and Western blot. NE enhanced the proliferation of human PASMC partly by affecting the expression of αenolase.Conclusion The data suggest that a wide range of signaling pathways may be involved in NEinduced proliferation of human PASMC, and α-enolase associated pathway may be an important one.