The mammalian target of rapamycin (mTOR) is a serine-threonine kinase downstream in the PI3K-Akt pathway, which belongs to the phosphatidylinositol kinase-related kinase (PIKK) family. The mTOR palys an important role in cell cycle regulation and protein synthesis. mTOR signaling pathway is evolutionarily conserved, which can integrate and converge a wide range of signals, including intracellular and extracellular nutrients, growth factors, energy and stress conditions, and has a crucial role in vertebrate growth control. The upstream regulation and downstream effects mediated by mTOR form a network of critical growth signaling pathways. Hence, dysregulation of components within mTOR signaling network result in impaired internal environment conditions, and first meiotic division can also be influenced if occurring during starfish and sea urchin oocyte maturation. However, its functions in mammalian meiosis are unclear. The localization and function of mTOR during mouse oocyte meiotic maturation were investigated with the oocytes of Kunming mouse. Location of mTOR was examined in Germinal vesicle (GV) stage, Germinal vesicle breakdown (GVBD) stage and second metaphase (MⅡ) stage during mouse oocyte maturation by immunofluorescence technology. The rate of GVBD and polar body extrusion (PB1) during mouse oocytes maturation was also detected by treatment with different concentration rapamycin (0.5 g/L, 2.5 g/L, 3.3 g/L, 5.0 g/L, 10 g/L ). Immunofluorescent staining showed that mTOR mainly is located on nuclear membrane during GV stage, distributed with the chromosome after GVBD, and distributed with the spindle apparatus during MⅡ stage. The oocyte maturation was inhibited by treatment with rapamycin, and the inhibitory action was concentration dependent, when the drug concentration reached to 3.3 g/L, the disparity was significant (P < 0.05). Meanwhile, the location and morphous of mTOR were changed: under treatment with 3.3 g/L rapamycin, mTOR protein expression became obviously weaker and distributed more in intranuclear in the stage of GV; and didn't distribute with the chromosome after GVBD, the morphous of chromosome was changed. The mTOR can not be detected in MⅡ stage, and the chromosome arrangment was irregular. The results suggest that the expression and distribution of mTOR shows stage specificity during mouse oocyte maturation, rapamycin had an effect on mouse first meiotic division, including chromosome arrangment and spindle formation, demonstrating that a rapamycin-sensitive pathways is involved in this mechinism. mTOR plays an important role during procedure of GVBD and first polar body extrusion, which could regulate maturation process of mouse oocyte through the changes of its expression and localization.