Abstract: Recent studies have shown that miR-100 can act as oncogene or tumor suppressor gene in different tumors. It not only plays an important role in the development and progression of a variety of tumor types（cervical cancer， prostate cancer， bladder cancer， lung cancer， etc）， but also can resensitize tumor cell towards chemotherapeutic drugs. miR-100 is expected to become a new target for cancer treatment and a new molecular marker for prognostic predictors. In this review， we summarize the latest progresses， both domestic and overseas， in the roles of miR-100 in the tumor development.