Abstract: Cyclin dependent kinase(CDK) 4/6 inhibitors have shown significant effects in preventing tumor growth, disease development, and improving survival rates. They are currently a hot spot in the research and development of anti-cancer drugs and have been clinically applied in the treatment of breast cancer and non-small cell lung cancer. CDK4/6 is amplified and overexpressed in gastrointestinal tumors. CDK4/6 inhibitors have been studied in gastrointestinal tumors. This article reviews the recent clinical trials of CDK4/6 inhibitors in esophageal cancer, gastric cancer, and colorectal cancer.