Abstract: Objective To explore the role of miR-144/451 in regulation of transferrin receptor 1(Tfr1). Methods Mean fluorescence intensity(MFI)of Tfr1 of cells from fetal liver, bone marrow, spleen, and peripheral blood of wild-type mice(WT)and miR-144/451 knockout mice(mKO)was detected by flow cytometry. Quantitative real time PCR(qRT-PCR)was used to detect mRNA levels of Tfr1 in nucleated erythroid cells in bone marrow and spleen. Results Compared with WT mice, the MFI of Tfr1 of erythroid cells of fetal liver, bone marrow, spleen, and peripheral blood in mKO mice was significantly decreased(P<0.05 or P<0.01). The expression of Tfr1 mRNA increased in nucleated erythroid cells in bone marrow and spleen of mKO mice compared to WT mice. Conclusion miR-144/451 is involved in the regulation of Tfr1 in red cells, which may affect erythropoiesis. This article leads a direction for anemia reasons of mKO rats.