Lymph node metastasis is an important aspect for tumor metastasis, which accounts for a majority of cancer death. Non-invasive imaging techniques play a more important role than traditional lymph node biopsy for diagnosis of metastatic lymph nodes. However, non-specific information of lymph node such as size and morphology could only be obtained in traditional imaging techniques, which always bring about mission detection. Thus, lymph-targeted contrast agents are attracting much interest. Presently, most contrast agents are based on the mechanism of passive targeting, which could be affected by the number and function of macrophages in the lymph nodes. Therefore, it is beneficial to study the tumor lymphatic metastases through developing new lymph-targeted contrast agents, which could bring fresh prospect for tumor diagnosis and treatment. The paper reviews the progress of lymph-targeted contrast agents and their diagnosis technology for cancer.