Objective To investigate the effect of myeloid differentiation factor 88 inhibitor ST2825 on the autophagy of THP?1 cells infected by re?combinant mycobacterium smegmatis. Methods The myeloid differentiation factor 88 inhibitor ST2825 was applied on the THP?1 cells infected by recombinant mycobacterium smegmatis,and three groups were defined:the test group with ST2825 treatment,the control group without ST2825 treatment,and the blank group. Autophagosomes were observed under the fluorescence microscope,and the mRNA expression of Beclin?1 gene and Bcl?2gene was analyzed by RT?PCR. Results Compared with the control group,the number of autophagy fluorescent dots in the test group was ob?viously reduced(P<0. 05),and the expression levels of Beclin 1 gene and Bcl?2 gene were declined as indicated by the RT?PCR detection. Con?clusion The myeloid differentiation factor 88 inhibitor ST2825 might inhibit the autophagy of THP?1 cells through interfering the separation of Be?clin?1 and Bcl?2.