Abstract: Objective To investigate the expression level of HOXB7 in non-small cell lung cancer (NSCLC) tissues and cell lines, and the effect of HOXB7 expression on the proliferation of NSCLC cells A549. Methods Real-time quantitative PCR and immunohistochemical method were performed to detect the relative expression of HOXB7 in NSCLC tissues and cell lines. Si-HOXB7 were transfected into A549 cells to downregulate HOXB7 expression, and qPCR was used to test the transfection efficiency. Pathological data were used to analyze the relationship between HOXB7 expression and the prognosis of NSCLC patients. MTT and flow cytometry analysis were performed to detect the effect of HOXB7 on the proliferation of NSCLC cells. Results HOXB7 were highly expressed both in NSCLC tissues and cell lines, compared with their corresponding normal tissues and cell lines. NSCLC patients with high HOXB7 expression showed poor overall survival. si-RNA transfection could significantly decreased HOXB7 expression in NSCLC cells A549, and down-regulating of HOXB7 expression could inhibit NSCLC cells A549 proliferation. Conclusion Upregulated HOXB7 could promote NSCLC cells proliferation.