Abstract: Objective： To analyze the correlation between synuclein gamma (SNCG) and matrix metalloproteinase-9 (MMP-9) and the clinicopathological features of tumor,we investigated the expression of SNCG and MMP-9 in oral and maxillofacial carcinoma and its adjacent tissues. Methods：Immunohistochemistry method was used to detect the expression of SNCG and MMP-9 in oral and maxillofacial carcinoma and its adjacent tissues. Results：The incidence rate of SNCG and MMP-9 in oral and maxillofacial carcinoma was 78.0% (117/150) and 68.68%(103/150), respectively. While that of SNCG and MMP-9 in its adjacent tissues was 8.0%(11/150) and 14.0%(21/150), respectively. There were significantly differences in SNCG and MMP-9 between them(P<0.001). The incidence rates of SNCG and MMP-9 were higher in poorly or medium differentiated (P<0.001). However, the expression of SNCG and MMP-9 between poorly differentiated and well differentiated carcinoma had no significant difference. According to stages, the incidence rates of SNCG and MMP-9 in Ⅲ-Ⅳ period were significantly higher than those inⅠ-Ⅱ period, and there were significant difference (SNCG: χ2＝4.20, P＝0.041; MMP-9: χ2＝26.66, P＝0.000). The expression of SNCG and MMP-9 in metastatic tumor were higher (SNCG: 90.77%；MMP-9:93.85% ) than that in non-metastatic tumor (SNCG: 68.24%; MMP-9: 49.41%), and there were significant difference(SNCG: χ2＝10.09, P＝0.0014; MMP-9: χ2＝33.80, P＝0.000). Conclusions：The excessive expression of SNCG and MMP-9 in oral and maxillofacial carcinoma,which was positively associated with the pathologic process, differentiation degree of carcinoma, and TNM stages of tumor.The expression of SNCG and MMP-9 are expected to be the marker in the tumor of oral and maxillofacial carcinoma for the judgment of advancement and prognosis.