Objectives: This study was carried out to investigate the effects of Sasammaickmoondong-tang (SME) on gastric mucosal lesions induced by indomethacin in mice. Methods: The normal group was no inflammation-induced mice. The control group was gastro-inflammation-induced mice. The sample group was mice administered SME after gastro-inflammation elicitation. Results: In the common morphology and histochemical change, the control group was observed with various injury-mucous surface cell, micro-villi, paneth cell, surface epithelial cell, goblet cell - by hemorrhagic erosion, while the sample group was as same as the normal group. In the immunohistochemical change, the distributions of COX-1, Bcl-2, and BrdU treated with SME were noticeably higher than in the control group (p<0.05). The distributions of TUNEL, NF-B, COX-2, IL-2R-, NK-1.1, ICAM-1, and CD11b/18 in those treated with SME were noticeably lower than in the control group (p<0.05). Finally, the distribution of SBA was the same as in the normal group. Conclusions: According to the above results, it is supposed that Sasammaickmoondong-tang is applicable to gastric mucosal lesions.