Abstract: Objective To study the effect of long non-coding RNA (LncRNA) metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) on the proliferation and apoptosis of human umbilical vein endothelial cells (HUVECs).Methods We constructed RNA interference (RNAi) plasmid vectors for MALAT1 and then transfected them into HUVECs by liposome method.A blank control and a negative control group of HUVECs were also established.The expression of MALAT1 in HUVECs of the three groups was detected with quantitative real-time PCR (qRT-PCR).The proliferation of HUVECs was determined with caerulein and cholecystokinin octapeptide (CCK-8) assay and the apoptosis of the HUVECs was analyzed by flow cytometry with annexin Ⅴ-fluorescein isothiocyanate/propidium iodide (FITC/PI) double staining.Results The relative MALAT1 expression was 0.051±0.03 in MALAT1-RNAi transfected HUVECs and significantly higher than that of in blank and negative control HUVECs (both P<0.01);the absorbance values (A) of culture medium for MALAT1-RNAi transfeced HUVECs were 0.072±0.087 and 1.115±0.077 at 48 and 72 hours of incubation and were both significantly lower than those of the blank and negative control HUVECs (P<0.05 for all);the apoptosis rate of MALAT1-RNAi transfeced HUVECs was 14.08±1.05% and significantly higher than that blank and negative control HUVECs (both P<0.01).Conclusion MALAT1-RNAi could inhibit the proliferation and promote the apoptosis of human umbilical vein endothelial cells.