Abstract: Objective To study the effect of bevacizumab (Avastin) on pulmonary microvascular angiogenesis induced by lung cancer. Methods The effects of Avastin on cell growth, cell cycle and apoptosis of lung microvascular endothelial cells were assayed by flow cytometry. Results Avastin inhibited the growth of lung microvascular endothelial cells and induced increase of cell apoptosis index in a concentration-dependent manner. With the increment of Avastin concentration from 25 to 100 μg/ml, avascular area increased from 0.944±0.073 cm2 to 5.189±0.192 cm2, and the cell apoptosis index increased from 32.5%±1.5% to 39.25±1.6%. Conclusion Avastin can inhibit the growth and induce apoptosis of lung microvascular endothelial cells in three-dimensional culture, possibly in association with cell cycle arrest in G0/1 phase.