After the surgery and or chemotherapy, it is still important to review the follow-up of tumors, especially malignant tumors. The purpose of review is to understand whether there is any recurrence problem, because the most important feature of malignant tumor is recurrence and metastasis. It is difficult to predict whether an individual will recur or not based on the pathological stage and treatment, which means there is no effective predictor or indicator at present. It can only be done according to the condition and in accordance with the guideline recommended norms, with timely review to detect problems and deal with them in time to improve the chance of cure or maximize survival. Therefore, postoperative review is very important and should be given sufficient attention. So, what do we need to pay attention to in the review? First of all, the frequency of review is clear. Generally, after surgery, the attending doctor will inform the patient of the late follow-up plan according to the specific condition. It is recommended to follow the follow-up plan without special circumstances. Take the post-operative follow-up of gastrointestinal cancer as an example. Within 2 years after surgery, it should be reviewed once every three months; 2-5 years after surgery, it should be reviewed once every six months; after 5 years after surgery, it can be reviewed once a year. Of course, for patients with early stage gastrointestinal cancer after radical surgery, they can be reviewed once every half year within 5 years, after all, the risk of early review is low. Secondly, to clarify the content of the review, the routine postoperative review needs to improve blood routine, blood biochemistry, gastrointestinal tumor markers, and in case of gastric cancer patients, vitamin deficiency can be checked selectively. For lung screening, the main tool is chest X-ray or chest CT, and it is best to do chest X-ray and CT at intervals. If there are no nodules and other problems in the past, plain CT is sufficient, but if there are nodules in the last review, it is better to enhance them, except for tumor metastasis; for abdominopelvic organ examination, ultrasound or CT is recommended, and it is also recommended to do ultrasound and CT at intervals, and CT is recommended to enhance CT to deal with understanding whether there are problems in abdominopelvic organs, and also to look at retroperitoneal lymph nodes. Also, if possible, it is best to get a review from the primary care doctor, because the primary care doctor understands the condition and the entire treatment process and can give more targeted examination recommendations. If you need to change doctors, it is better to fix one or two in your specialty, rather than changing to a different doctor each time. Also, do not let go of suspicious test results easily. Talk to your primary care physician, compare the results with previous tests, and add other test tools if necessary to exclude the possibility of recurrence. If it is not clear, but suspected, make sure to shorten the time interval for the next review, not in the usual 3 months or 6 months, but preferably in 1 month.