Abstract: Fluorouracil is important in the treatment of colorectal cancer. Compared with traditional 5fluorouracil， the oral fluorouracil（including UFT， doxifluridine， capecitabine， S1， etc） has numerous advantages such as： high efficiency， low toxicity， ease of application and so on. It is widely used in clinical. This review analyzes the mechanism of 5FU and the development of oral fluorouracil， and the recent status and progression of oral fluorouracil in treatment of advanced colorectal cancer.