Abstract: Soluble resistance-related calcium-binding protein, SORCIN, is a 22 kDa calcium binding protein with "penta-EF hand", which participates in the regulation of intracellular calcium homeostasis in cells. SORCIN is highly expressed in many tissues such as hearts and brains. It is overexpressed in some of cancer tissues as well. Recently, a large amount of clinical data showed that SORCIN was closely related to drug resistance in cancer. Meanwhile, basic research found that SORCIN participates in the formation of multidrug resistance (MDR) and is related to severity and poor prognosis of tumors. Moreover, it may also regulate MDR induced by ATP-binding cassette transporters. Therefore, SORCIN is expected to become a new target for diagnosis and treatment of MDR. The present review summarizes recent progress in SORCIN study and its effect on MDR.