Objective To investigate the expression and immune function of NOD2 signal in MyD88-/- mice. Methods MyD88-/- mice and wild-type C57 BL/6 mice were characterized by PCR. Mice model of pulmonary infection was constructed by tracheal instillation of BCG vaccine strain(attenuated strain of Mycobacterium). PBS tracheal instillation was used as negative control.Peripheral blood sample and lung tissue were collected aseptically 24 h after Mycobacterium challenge. Real-time PCR and Western blot were used to detect the expression of NOD2 gene and protein. IL-6 level in the peripheral blood was determined by enzymelinked immunosorbent assay. Results The expression of NOD2 protein in BCG infected mice was significantly higher than PBS negative control group. NOD2 protein expression in MyD88-/- mice was higher than in wild-type mice. BCG infection was associated with higher NOD2 protein expression than infection-free PBS control in both groups of animals. The IL-6 level in peripheral blood was significantly higher after BCG infection than PBS group in both MyD88-/- mice and wild type mice. Conclusions BCG can activate the NOD2 signaling pathway when MyD88-dependent pathway is deficient.