The normal value of the anteroposterior diameter of the left liver is 4.1-7.4 centimeters. At present, there is no uniform standard for the normal value of the liver, and the draft standard for the normal value of the liver adopted by the 1983 Chinese Medical Association Ultrasonic Diagnostic Symposium for reference has the normal value of the anterior and posterior diameters of the left liver as 4.1-7.4 cm, and the upper and lower diameters of the left liver as 4.0-8.3 cm. The thickness and length of the left half of the liver is measured in a longitudinal sonogram through the abdominal aorta as a standard section, i.e., a subxiphoid longitudinal section with the abdominal aorta as the point of reference, which allows the measurement of the upper and lower diameters of the left lobe of the liver along with the anteroposterior and posterior diameters, and observation of collateral circulation of the portal vein, which is seen to be open in the umbilical vein during portal hypertension. If the anteroposterior diameter of the left liver is found to be abnormal, it is necessary to go to the hospital in time, to clarify the diagnosis and treatment plan, to use drugs under the guidance of the doctor, and to avoid self-medication.