The earliest organ used for ultrasonography is the liver, so ultrasound can be the preferred diagnostic imaging method for all liver-related diseases. The most basic aspects of ultrasound examination of the liver are the size and shape of the liver, the echogenicity of the liver parenchyma and the internal structures of the liver, such as the portal veins, hepatic veins and intrahepatic bile ducts. This is the basis for diagnosing those abnormalities such as diffuse liver lesions: various types of acute and chronic hepatitis and liver damage from various causes will have changes such as enlargement and volume reduction of the liver and thickening and enhancement of the parenchymal echogenicity of the liver; manifestations of cirrhosis such as portal, necrotic and biliary; manifestations of schistosomiasis and manifestations of fatty liver and alcoholic liver. It is possible to diagnose fluid-containing lesions of the liver, such as liver cysts, polycystic liver, liver abscesses, and restricted dilatation of intrahepatic bile ducts. Parasitic diseases of the liver, such as hepatic encysticercosis, etc. Non-neoplastic focal parenchymal lesions of the liver, such as limited inflammation and necrosis, intrahepatic calcified foci, hepatic tuberculosis, and intrahepatic foreign bodies. Benign and malignant tumors of the liver, such as hemangioma, malignant tumor, lipoma, mucinous tumor, hepatocellular carcinoma, hepatoblastoma, and metastatic liver cancer. In addition, ultrasound has certain clinical application value for the treatment of liver cancer and some evaluation of liver cancer after treatment. Ultrasound examination of the liver can assist clinical diagnosis of liver-related diseases.