The current study demonstrated that holothurian glycosaminoglycan (AHG) could successfully improve immunoregulation activity in vitro, and possesses the capacity to restore CY induced immunosuppression in vivo. Based on these findings and the data accumulated, it was suggested that AHG has huge potential to be an effective immunomodulatory agent and adjuvant in clinical treatment of all cancer patients. Further investigation should be conducted to understand the overall intracellular process associated with the AHG-induced immune response for the development of a novel marine medicine.