Abstract：Objective：To investigate the effect of QIU's Neiyi Prescription on mitogen-activated protein kinase/extracellular regulated protein kinase1/2 (MAPK/ERK1/2) signaling pathway of adenomyosis model mice and its mechanism. Methods：A total of 60 cases of eight-week-old non-pregnant female ICR mice were randomly divided into the sham-operation group，the model group，the positive control group (3.60 g/kg gestrinone)， and the low- dose， medium- dose and high- dose Chinese medicine groups (1.80， 3.60， 7.20 g/kg QIU's Neiyi Prescription)，with 10 mice in each group. The pathological changes in histomorphology of endometrium in mice were evaluated by endometrial histomorphological scores；the expression levels of estrogen (E2) ， estrogen receptor (ER) ， and apoptosis- related proteins [cysteinyl aspartate- specific proteinase-3 (Caspase-3)，the Bcl-related protein (Bax)，B cell lymphoma-2 (bcl-2)] in uterine tissue of mice in each group were detected by ELISA；the mitogen-activated protein kinase (MEK-2)，extracellular regulated protein kinase 1/2 (ERK1/2)，nuclear transcription factor (NF- κB)，proto- oncogene (c- jun) and immediate early gene (c- fos) in uterine tissue of mice in each group were detected by Western Blot. Results：The endometrial histomorphological score in the model group was increased when compared with that in the sham-operation group (P＜0.05)；the endometrial histomorphological scores of mice in the lowdose， medium- dose and high- dose Chinese medicine groups and the positive control group were decreased when compared with those in the model group，and the endometrial histomorphological scores in the Chinese medicine groups were decreased in a dose-dependent manner (P＜0.05). When compared with those in the sham-operation group，the protein expressions of Caspase- 3，Bax in uterine tissue of mice in the model group were decreased (P＜0.05)，the protein expressions of bcl-2，E2，ER，MEK-2， ERK1/2， NF- κB， c- fos and c- jun were increased (P＜0.05). When compared with those in the model group，the protein expressions of Caspase- 3，Bax in uterine tissue of mice in the low-dose，mediumdose and high-dose Chinese medicine groups and the positive control group were increased (P＜0.05)；the protein expressions of Bax，E2，ER，MEK- 2，ERK1/2，NF- κB，c- fos and c- jun were decreased (P＜ 0.05)；the protein expressions of Caspase-3，Bax in uterine tissue of mice in the Chinese medicine groups were increased in a dose- dependent manner (P＜0.05)； the protein expressions of bcl- 2， E2， ER， MEK- 2， ERK1/2， NF- κB， c- fos and c- jun were decreased in a dose- dependent manner (P＜0.05). Conclusion： QIU's Neiyi Prescription has a therapeutic effect on mice with adenomyosis， and its action mechanism is related to regulating the expressions of MAPK/ERK1/2 signaling pathway-related proteins in uterine tissue of mice and promoting cell apoptosis in adenomyosis lesion tissue of mice.