〔Abstract〕 Objective To construct Csf1r-CreERT2R26REYFPreporter gene mice and assess the efficacy of Csf1r-CreERT2-mediated enhancement of CSF1R in CD45+cells labeled with yellow fluorescein protein EYFP. Methods Csf1r-CreERT2mice were crossbred with R26REYFPhomozygous mice, and Csf1r-CreERT2R26REYFPmice were identified through PCR and Western Blot analyses.Flow cytometry was employed to evaluate CSF1R tag-efficiency in CD45+cells across different mouse tissues following tamoxifen induction. Results Csf1r-CreERT2R26REYFPreporter gene mice were acquired.In addition, it was found that Csf1r-CreERT2-mediated EYFP could effectively mark CSF1R in various tissues of mice and CD45+cells in different locations.Compared to the R26REYFPgroup, the highest labeling efficiency was observed in the brain tissue(P<0.001), the lowest in the thymus tissue(P<0.05), and no significant difference was observed in the spleen tissue. Conclusion Adult Csf1r-CreERT2mice and R26REYFPmice are effective ways to obtain Csf1r-CreERT2R26REYFPinduced conditional fluorescence mice.Csf1r-CreERT2can mediate EYFP to effectively trace CSF1R in CD45+cells in different parts of mice.