Colorectal cancer (CRC) is the most common malignant tumor of digestive system. At present, it is generally accepted that CRC is still curable if it can be early diagnosed. Tumor markers are molecules that reflect the biological behaviors of tumors and can predict tumors to a certain extent. Test of tumor markers is less invasive, but the sensitivity and specificity need to be improved. In recent years, many tumor markers of CRC have been detected not only at the protein level, but also at the gene level. This article reviews research progresses.