To examine the potentiation of Macrolepiota procera extracts (MPE-4) to act as adjuvant enhancing the tumor specific anti-tumor immune response, tumor vaccine prepared by boiling (HK vaccine) admixed with MPE-4 and immunized in mice. Vaccination of mice with HK vaccine in combination with MPE-4 resulted in higher inhibition in tumor metastasis compared with the mice of HK vaccine alone treatment against live syngeneic tumor cell challenge. The splenocytes from mice immunized HK vaccine mixed with MPE-4 was able to elicit a stronger cytotoxic T lymphocyte (CTL) response as compared with HK vaccine alone. In addition, the splenocytes from MPE-4 admixed HK vaccine immunized mice secreted a higher concentration of Th1 type cytokine such as IFN-${gamma}$, and GM-CSF. Furthermore, the adoptive transfer of splenocytes from mice immunized HK vaccine and MPE-4 led to a more robust anti-tumour response than the HK vaccine alone. Overall, these results indicate that MPE-4 is a good candidate adjuvant of anti-tumor immune response.