Abstract: Multidrug resistance (MDR) seriously affects the clinical efficacy of chemotherapeutic drugs. One of the main mechanisms of MDR is the overexpression of P-glycoprotein (P-gp) in tumor cells that reduces the intracellular drug concentrations and limits the effective use of chemotherapeutic drugs. Accordingly, application of P-gp inhibitors that can reverse tumor MDR is an effective strategy to enhance the anti-tumor effect of chemotherapeutic drugs. In recent years, D-α-tocopheryl polyethylene glycol 1000 succinate (TPGS) has been widely applied as the potential P-gp inhibitor for its excellent P-gp inhibition effect as well as good safety. In this paper, we reviewed the P-gp inhibitors, the mechanisms of TPGS in reversing P-gp-mediated MDR and the application of TPGS-based nano-drug delivery system.