To study the effect of miR-199a on the sensitivity of OV2008 and C13* cells to cisplatin and investigate its mechanism of action. Real-time polymerase chain reaction(PCR) and Western blot were applied to detect the expression level changes of mammalian target of rapamycin (mTOR) in OV2008 and C13* cells before and after transfecting the cells with the mimics and inhibitor of miR-199a with Lipofectamine 2000.We constructed luciferase reporter vectors of mTOR and then transfected OV2008 cells with the mimics of miR-199a with Lipofectamine 2000 to study the regulation of miR-199a's downstream target genes. The expression level of mTOR was significantly higher in C13* than OV2008 cells (P<0.05). After OV2008 and C13* cells were transfected with the mimics and inhibitor of miR-199a, real-time PCR and Western blot showed that the mimics of miR-199a repressed the expression of mTOR; and the inhibitor of miR-199a promoted the expression of mTOR. After transfecting OV2008 cells with the mimics of miR-199a and luciferase reporter vectors of mTOR, renillaluciferase reporter gene analysis indicated the expression level of mTOR was negatively regulated by miR-199a. miR-199a regulates the sensitivity of ovarian cancer cells to cisplatin through modulating expression of mTOR, and involves in the cisplatin resistance process of ovarian cancer cells.