This study aims to construct the plasmid of human Runx1 and observe its possible effects on Runx1 gene expression in human pulmonary adenocarcinoma cells (A549). The shRNA sequence targeting human Runx1 was designed and synthesized, then inserted into pSuper plasmid by DNA recombination technology. The recombinant plasmid was confirmed by bacterial colonies PCR, enzyme digestion analysis and DNA sequencing. A549 cells were transfected by Runx1 shRNA plasmid. The inhibition efficiency of pSuper-Runx1-shRNA plasmid on Runx1 at mRNA level and protein level were measured with real-time PCR and Western blot. The results of real-time PCR and Western blot indicated that the mRNA and protein levels of Runx1 in A549 cells were inhibited by the pSuper-Runx1-shRNA expression plasmid, and the inhibition rate were 33% and 50%, respectively.