Objective To assess the impact of miR-429 on lung adenocarcinoma cell SPC-A1 growth inhibition.Methods Pre-miRTM miR-429 precursor was synthesized and transfected to the SPC-A1 cells by liposome; qRT-PCR assay was used to quantify the miR-429 expression levels; The proliferation of SPC-A1 cells was evaluated by Cell Counting Kit-8 (CCK8).The cell apoptosis was evaluated by Annexin V Assay; The cell cycles of each group were assayed by flow cytometry;Western-blot was used to analyze the expression of cylines.Results The expression level of miR-429 was highly induced after transfection (P ＜ 0.001) ;CCK-8 assay showed the cell proliferation activity of pre-miR-429 group was lower than that of blank and control group 48h and 72 h after transfection(P =0.0167,0.0383,P =0.0320,0.0465),whereas the apoptosis rate had no significant difference between pre-miR-429 and control 24h after transfection by Annexin V Assay(P ＞ 0.05) ; The flow cytometry at 48h after transfection showed that miR-429 decreased the percentage of cells in G1 phase,but increased in S phase,indicating the cell cycle arrest at S phase(P =0.0010,0.0010 ; P =0.0068,0.0133) ; however,the expression level of Cyclin E in pre-miR-429 group had no difference compared with control.Conclusion miR-429 could inhibit cell proliferation and promote cell cycle arrest of lung adenocarcinoma cell SPC-A1.miR-429 may play a potential tumor suppressor role in lung adenocarcinoma cell SPC-A1.