Objective. To investigate the role of matrix metalloproteinase-7 （MMP-7） expression in caricinogenesis and progression of gastric cancer.Methods. We studied MMP-7 expression and microvessel density （MVD） in adjacent mucosa and primary foci of 113 cases of gastric cancer by streptavidin -biotin -immunoperoxidase method using anti -MMP-7 and anti-CD34 antibodies. MMP-7 expression and mean MVD were compared with clinicopatholog-ical features of gastric cancer

with the relationship between MMP-7 expression and MVD concerned in gastric cancer.Results. MMP-7 showed positive expression in adjacent mucosa of gastric cancer （29.20%

33/113）

less than that in gastric cancer （69.03%

78/113）. MMP-7 expression in primary foci of gastric cancer was positively correlated with tumor size

invasive depth

metastasis and TNM staging （P<0.05）

but not with differentiation or growth pattern of gastric cancer （P>0.05）. Positive correlation of mean MVD with tumor size

invasive depth

metastasis and TNM staging was found （P<0.05）

despite no relationship between mean MVD and differentiation of gastric cancer （P>0.05）. Mean MVD was dependent on MMP-7 expression in gastric cancer （P<0.05）.Conclusion. Up-regulated expression of MMP-7 played an important role in carcinogenesis and progression by participating in growth

invasion

metastasis and angiogenesis of gastric cancer. MMP-7 expression could be regarded as an effective and objective marker to reflect the biological behaviors of gastric cancer.