Mammalian target of rapamycin (mTOR) is a key downstream molecule of PI3K/Akt pathway. It integrates input signals from growth factors, nutrients and energy to regulate cell growth and proliferation via different cellular processes. Gene mutations of mTOR pathway-related proteins are very common in many carcinomas. Abnormal expression of these related proteins can result in aberrant hyperactivity of mTOR pathway. Therefore, mTOR-targeted therapy has shown promising role in the management of various cancers. This article reviewed the current status of researches on mTOR and its inhibitors in antitumor therapy.