Nanoemulsions (NE) are used widely in pharmaceutical drug formulations and vaccine preparation, and Acanthopanax senticousus polysaccharide (ASPS) is a natural bioactive compound with immunostimulatory activity. Therefore, NE-loaded ASPS is expected to provide immunological enhancement for effective treatment. In the present study, Acanthopanax senticousus polysaccharide (ASPS was encapsulated into nanoemulsions, the resultant ASPS–NE were coated with a negative charge, and the immune enhancement mechanism of these ASPS-NE formulations was analyzed. The immunosuppressive animal models (70 ICR mice, male) for the study were established using cyclophosphamide. In addition, the activation of splenocyte proliferation, phagocytosis of the macrophages, the ratio of CD4+ to CD8+, the concentrations of the cytokines in serum, Western blot analysis was used for the analysis of the P65/JNK/ikk α signaling pathway in the peritoneal macrophage s. The results revealed that the ASPS-NE could stimulated the proliferation of splenocytes and enhance immunity. The ASPS-NE induced the expression of different cytokines (TNF-α, IFN-γ, IL-2, and IL-6), could activate the expressions of P65, JNK, and ikkα, and regulated the Th1/Th2 cytokines. These findings demonstrated the potential of ASPS-NE formulations for drug delivery and to induce potent and sustained immune responses.