Coix seed is a dry mature seed of Gramineae plant Coix. It has been confirmed that a plurality of components thereof have pharmacological effects. The mechanism of Coix seed against tumor includes the following aspects:(1) Inhibit the proliferation of tumor cells.(2) Inhibit the invasion and metastasis of tumor cells.(3) Inhibit the formation of tumor blood vessels.(4) Induce apoptosis of tumor cells.(5) The synergistic and attenuating effects on chemotherapy.(6) Enhance the sensitivity of tumor cells to radiation.(7) Adjust the body's immune function.(8) Relieve the pain of advanced tumors. In this paper, we summarized the research adcances of Coix seed foucusing on its anti-tumor effects.