Objective To construct the eukaryotic expression vector of the cancer suppressor gene, SEMA3B, and research the effects on malignant biological behavior of lung cancer A549 cells. Methods By reverse transcriptase-polymerase chain reaction (RT-PCR), the full length SEMA3B gene was amplified and then was inserted into pcDNA3.1. The recombinant plasmid pcDNA3.1-SEMA3B was confirmed correctly through double enzyme digestion and PCR identification, which was transfected into lung cancer A549 cells by lipid media transfection. The untransfected A549 and A549 transfected with pcDNA3.1 were used as controls. SMEA3B gene was detected by qRT-PCR and western blot. MTS assay, flow cytometry, and colony formation test were performed to evaluate the effect of overexpression of SEMA3B gene on A549 cell proliferation, apoptosis, cell cycle, and colony forming ability. Results The amplied fragment of SEMA3B gene by PCR was consistent with the anticipated result, the SEMA3B gene was cloned successfully. And the recombinant plasmid pcDNA3.1-SMEA3B was constructed successfully through gene sequence identification. After transfection of pcDNA3.1-SEMA3B, SEMA3B mRNA and protein expression levels were raised, and overexpression of SEMA3B gene in A549 cells significantly inhibited the proliferation of A549 cells, induced apoptotic cell death, blocked cell cycle in the G1 phase, and suppressed cell colony-forming ability. Conclusion The recombinant pcDNA3.1-SEMA3B is constructed successfully. SEMA3B gene can significantly inhibit the malignant biological behavior of lung cancer A549 cells.