The liver is a common site of metastasis for colorectal cancer. Liver metastases are present in 20%-25% of new colorectal cancer cases, while 40%-50% of surgically resected colorectal cancer cases will eventually develop liver metastases. Liver metastasis is the main cause of death in colorectal cancer, and how to improve the outcome of patients with liver metastasis has become one of the focal points in the field of colorectal cancer research. According to foreign literature, 50% to 60% of colorectal cancer patients will eventually develop liver metastases, and the proportion of liver metastases among patients with postoperative recurrence is as high as 70%, and about 70% of patients who died of colorectal cancer were found to have liver metastases in autopsies. It is generally believed that the incidence of simultaneous liver metastases is about 15%-25% and the incidence of heterochronic liver metastases is about 20%-25%, but the domestic data are generally lower than this figure. The diagnosis of simultaneous liver metastases mainly relies on preoperative examination and/or intraoperative exploration and, if necessary, intraoperative biopsy, whereas the diagnosis of heterochronic liver metastases mainly relies on regular postoperative follow-up review. Abnormal elevation of serum CEA is 4-10 months earlier than clinical detection of recurrent metastases, and its positive rate is generally up to 70% or more. Therefore, rechecking serum CEA every 2-3 months is an effective method for early detection of recurrence and metastases. Measurement of CEA in bile and duodenal fluid has the potential to detect liver metastases at an earlier stage. There is a lack of new markers that can replace CEA. Treatment of patients with liver metastases from colorectal cancer should be aggressive. If no treatment is given, the median survival is only 5-10 months; if active and effective treatment is given, the 5-year survival rate can reach 20%-40%, and the median survival is extended to 28-40 months.