Results: The serum MMP9 level in patients with salivary gland tumors (380.0±301.3 pg/ml) also patients with benign tumors (354.3±218.7 pg/ml) (354.3±218.7 pg/ml) were significantly lower than that in the healthy group (727.4±624.6 pg/ml) (Respectively p= 0.02 and p= 0.01). The gene discussed is MMP9; the disease is benign neoplasm.