Liver reserve function refers to the ability of the liver to withstand surgery, trauma, and damage from liver disease, that is, the ability of the liver to repair and regenerate itself. Clinical assessment of liver reserve function is important for whether liver surgery can be performed, the extent of surgical resection, whether liver failure will occur after surgery, and for determining the condition and prognosis of liver lesions. The main clinical modalities commonly used to examine liver reserve function are liver function, especially the determination of serum pre-albumin and bile acid values. The indocyanine green test is minimally invasive and simple, quick to perform, and is very important in determining the type and extent of hepatectomy. However, it sometimes does not accurately reflect liver function due to the influence of liver blood flow and bile excretion. There is also the Child score, which mainly includes albumin, total serum bilirubin, ascites, hepatic encephalopathy, and prothrombin time. Through the scoring of these five items, the grading of liver function can be determined, further improving the accuracy of liver function assessment. CT and MRI, not only can clarify the size of liver volume, but also can monitor the parameters of liver perfusion. All of these are commonly used in clinical practice to test liver reserve function and can be used in combination to further improve the accuracy of assessment.