Abstract: Macrophage was the strongest anti-body cells of phagocytosis，while，Brucella could multiply in the cell and could not be killed. Therefor，we established the infection model，for continuous research Brucella and it’s the host cell，and the interaction of baceria cell and host cell surface-associated membrane protein，discovering the intracellular interaction mechanism for next step. Infection of mouse macrophage cell line RAW264.7 with Brucella melitensi virulent strain 16M were performed 4 h at a cell/bacteria ratio of 1∶500. Brucella-infected marophages were examined by indirect immunofluorescence assay and transmission electron microscopy assay. The optimal concentration ratio of primary antibody and secondary antibody in indirect immunofluorescence assay were 1∶80 and 1∶80，and the membrane depression and the endocytosis bodies were observed by transmission electron microscope. Expriment reduced the environmental factors of the infection process, optimized concentration ratio of primary and secondary antibodies in indirect immunofluorescence assay，established infection model.

Key words: virulent Brucella melitensi strain 16M; macrophage cell line RAW264.7; indirect immunofluorescence assay; electron microscope assay