Abstract： Objective To investigate the effects of over-expression of homo sapiens eukaryotic translation elongation factor 1 alpha 2 (EEF1A2) on in vitro invasion and lung metastasis of human pancreatic cancer SW1990 cells.Methods Letivirus-mediated delivery of EEF1A2 was used to enhance the expression of EEF1A2 gene in human pancreatic cancer SW1990 cells,the SW1990 cells stably over-expressing EEF1A2 protein (SW1990/EEF1A2 cells) were obtained,and the parent SW1990 cells and SW1990/GFP cells were used as the control,and the expressions of EEF1 A2 mRNA and protein were determined by Real-time PCR and Western blotting.The invasion ability of cells was determined by Transwell assay.The lung metastasis model was established by injection of SW1990 cells into the tail vein.Whole lung tissues were harvested,and visible nodules on tung surface were counted macroscopically 8 weeks later.Results The EEF1 A2 mRNA expression of SW1990/EEF1A2 was 3.252 ± 0.344,which was significantly higher than those in SW1990/GFP cells (1.000 ±0.060) and SW1990 cells (0.944 ±0.041,t =2.255,2.305,P＜0.01) ; the EEF1A2 protein expression was 0.833 ± 0.050,which was significantly higher than those in SW1990/GFP cells (0.247 ± 0.035) and SW1990 cells (0.273± 0.041,t=0.572,0.559,P＜0.01).The ability of invasion of SW1990/EEF1A2 cells was (60 ±4) cells,which was sigmificantly higher than (33 ±4) cells in SW1990/GFP group and (26 ± 3) cells in SW1990 group (t =31.33,34.78,P ＜ 0.01).Furthernore,SW1990/EEF1 A2 cells had a much higher incidence of lung metastasis in nude mice than SW1990/GFP cells and SW1990 cells in vivo (100％ vs.20％,20％,P ＜ 0.05).Conclusions EEF1 A2 over-expression can obviously increase the in vitro invasion and lung metastasis of pancreatic cancer SW1990 cells.