Abstract: Abstract Objective: To construct a specific reporter vector to monitor the activity of mouse core binding factor a1 (Cbfa1) gene promoter and to analyze its transcriptional activity. Methods: A DNA segment of Cbfa1 gene promoter (-1000bp-+200bp) was amplified by nested-PCR from mouse genome DNA and correctly connected to promoterless vector PGL3-Basic by restriction enzyme MluI and XhoI. Recombinant plasmid pGL3-Cbfa1 was transiently transfected into osteoblastic cell line MC3T3-E1. The expression of luciferase was detected under the monitor of mouse Cbfa1 gene promoter (-1000bp-+200bp). Results: pGL3-Cbfa1 was the same as the design confirmed by restriction digestion and sequence analysis. High luciferase activity (35 fold greater than that of contro vector pGL3-Basic) was found in the pGL3-Cbfa1 promoter constructs. Conclusion: Mouse cbfa1 gene promoter luciferase reporter vector was successfully constructed and the reporter vetor laid the experiment foundation for screening of anti-osteoporosis medicine.