Extensive researches suggest that the metastasis of colorectal cancer involves multiple factors and genes.Recurrence and metastasis after surgery are the important reasons for poor prognosis of thesc patients with colorectal cancer.Tumorigenesis is a dynamic process.The levels of tumor markers are changed in different stages.It has not yet been found any kind of tumor markers specific for a certain type of colorectal cancer.The sensitivity and specificity of diagnoising colorectal cancer by detecting an individual tumor marker are not ideal.The better combination of tumor markers has its advantages,can improve the early diagnostic rate.Combining detection of tumor markers will improve the diagnostic yield.