As the immune organ of human body, lymph nodes are distributed in all parts of human body. Inflammation, virus direct invasion, the metastasis of malignant tumors in other organs, as well as the primary tumor of lymph node, will cause the immune response inside the lymph node, resulting in the change of lymph node size, shape and so on. Therefore, lymph node abnormalities may indicate the possibility of lesions to the organ in its region. In the course of treatment of clinical diseases, accurately judging the nature of lymph nodes not only affects the diagnosis of disease, but also can guide the choice of treatment plan and greatly improve the prognosis of patients. The qualitative diagnosis of lymph nodes plays an important role in the clinical treatment of malignant tumors and ultrasound examination technology has nowadays become a common imaging method for evaluating lymph nodes. This paper reviews the diagnostic value of different ultrasound techniques in lymph nodes.