Objective To investigate the effect of miR-145 on human lung adenocarcinaoma A549 cell proliferation and FSCN1 expression. Methods pmR-mcherry/miR-145 was constructed and transfected into A549 cell,then the expression of miR-145 and the proliferation of A549 cell were verified by QPCR and MTS assay, respectively.The situation of FSCN1 expression in A549 cell was detected by Western blot.Results pmR-mcherry/miR-145 vector was constructed successfully,and QPCR results indicated that miR-145 expressed effectively.Western blot results showed that FSCN1 was one of the targets of miR-145 in A549 cell.MTS assay results indicated that miR-145 inhibited the proliferation of A549 cell.Conclusion Overexpression of miR-145 can inhibit the proliferation of A549 cell, and FSCN1 was one of its target.