Abstract: Objective:To explore the changes of CD14 expression before and after THP-1 cells infected with Mycobacterium tuberculosis(Mtb). Methods:Mtb and phorbol myristate acetate(PMA)-differentiated THP-1 cells were incubated with the ratio of 10∶1,and Mtb infection cell model was established.The CD14 expression in THP-1 cells,PMA differentiated THP-1 cells and Mtb infected THP-1 cells were detected by flow cytometry. Results:The percentage of CD14 expression in THP-1 cells and PMA differentiated THP-1 cells was 5.5%,and 21.6%,respectively,whereas the percentage of Mtb phagocytosis rate was 7.7% and 93.0%,respectively.The percentage of CD14 expression in Mtb infected THP-1 cells was 27.5%. Conclusions:The CD14 expression in PMA differentiated THP-1 cells is increased,and the CD14 expression and Mtb phagocytosis rate in Mtb infected THP-1 cells are further increased.