Abstract: Tumor multidrug resistance (MDR) is an important factor that leads to cancer recurrence and metastasis. ATP-binding cassette transporters are widely present in humans, and their overexpression mainly induces MDR in tumor cells. Molecular imaging for the early monitoring of MDR tumors is helpful for clinicians to formulate effective treatment plans and improve tumor prognosis to a certain extent. This study briefly reviews the research progress on molecular imaging for MDR monitoring.