[Objectives] To investigate expression of MMP-1 in the scar tissue of skin and oral mucosa,and to explore if there is the significance of MMP-1 in the scar of skin and oral mucosa.[Methods]All samples were collected from surgical postoperative soft tissue from Department of Oral and Maxillofacial Surgery and Plastic Surgery in the Affiliated Qingdao Hiser Medical Center of Qingdao University Medical College,including 22 samples of dermal scar tissue,20 samples of normal skin tissue,and 13 samples of oral mucosal scar tissue,and 20 samples of normal oral mucosal tissue. HE staining was used to observe the morphology and collagen arrangement of fibroblasts in the scar tissue,the expression of MMP-1 in different tissue was observed by immunohistchemical staining. [Results] The positive expression rates of MMP-1 in skin scar tissue,oral mucousal scar tissue,normal skin tissue and normal mucosal tissue were 27. 27%,69. 23%,5. 00%,10. 00%. Comparison of positive expression of MMP-1 in skin scar tissue and oral mucosal scar tissue: the positive expression rate of MMP-1 in oral mucosal scar tissue was higher than that of MMP-1 in skin scar tissue,and the statistically significant difference was found between them( P < 0. 05).Comparison of positive expression of MMP-1 in skin scar tissue and normal skin tissue: the positive expression in skin scar tissue was higher than that in normal skin,and the statistically significant difference was found between them( P < 0. 05). Comparison of positive expression of MMP-1 in oral mucosal scar tissue and normal oral mucosal tissue: the positive expression rate of MMP-1 in oral mucosal scar tissue was higher than that in normal mucosal tissue,and the statistically significant difference was found between them( P < 0. 05). Comparison of positive expression of MMP-1 in normal oral mucosal tissue and normal skin tissue: the positive expression rate of MMP-1 in oral mucosal scar tissue was higher than that in normal mucosal tissue,and there was no statistically significant difference between them( P > 0. 05). [Conclusions] The positive expression of MMP-1 was different from that in the scar tissue of the oral mucosa,indicating that MMP-1 might be related to the severity of scar formation in different tissues. [Objectives] To investigate expression of MMP-1 in the scar tissue of skin and oral mucosa, and to explore if there is the significance of MMP-1 in the scar of skin and oral mucosa. [Methods] All samples were collected from surgical postoperative soft tissue from Department of Oral and Maxillofacial Surgery and Plastic Surgery in the Affiliated Qingdao Hiser Medical Center of Qingdao University Medical College, including 22 samples of dermal scar tissue, 20 samples of normal skin tissue, and 13 samples of oral mucosal scar tissue, and 20 samples of normal oral mucosal tissue. HE staining was used to observe the morphology and collagen arrangement of fibroblasts in the scar tissue, the expression of MMP-1 in different tissue was observed by immunohistchemical staining. [Results] The positive expression rates of Comparison of positive expression of MMP-1 in MMP-1 in skin scar tissue, oral mucousal scar tissue, normal skin tissue and normal mucosal tissue were 27. 27%, 69.23%, 5.00%, 10.0% skin s car tissue and oral mucosal scar tissue: the positive expression rate of MMP-1 in oral mucosal scar tissue was higher than that of MMP-1 in skin scar tissue, and the statistically significant difference was found between them (P <0.05) . Comparison of positive expression of MMP-1 in skin scar tissue and normal skin tissue: the positive expression in skin scar tissue was higher than that in normal skin, and the well significant difference was found between them (P <0.05). Comparison of positive expression of MMP-1 in oral mucosal scar tissue and normal oral mucosal tissue: the positive expression rate of MMP-1 in oral mucosal scar tissue was higher than that in normal mucosal tissue, and the well significant difference was found between them (P <0.05). Comparison of positive expression of MMP-1 in normal oral mucosal tissue and normal skin tissue: the positive expression rate of MMP-1 in oral mucosal scar tissue was higher than that in normal mucosal tissue, and therewas positive quite of difference between them (P> 0.05). [Conclusions] The positive expression of MMP-1 was different from that in the scar tissue of the oral mucosa, indicating that MMP-1 might be related to the severity of scar formation in different tissues.