Background: Enterococcus faecalis 2001 is a probiotic lactic acid bacterium and has been used as a biological response modifier (BRM). From physiological limitation of bacterial preservation in storage and safety, the live E. faecalis 2001 has been heat-treated and the BRM components containing high level of β-glucan, named EF-2001, were prepared. Method: The heat-treated EF-2001 has been examined for the antioxidative potential for radical scavenging and anti-tumor activities as well as immune-enhancing response in mice. Lymphocyte versus polymorphonuclear leukocyte ratio was increased in mice upon treatment with EF-2001. The number of lymphocytes was increased in the EF-2001-treated group. In the mice bearing two different Ehrlich solid and Sarcoma-180 carcinomas, the treatment with EF-2001 resulted in anti-tumor action. Tumor-suppressive capacity upon treatment with EF-2001 was significantly increased compared to normal controls. Results: During the time interval administration of 5 weeks between the priming and secondary administration of EF-2001, the expression and production levels of TNF-α were also observed in the EF-2001administered mice. Additionally, anti-tumor activity examined with the intravenous administration of EF 2001 with a 34 time intervals was also observed, as the growth of Sarcoma180 cells was clearly inhibited by the EF-2001. Conclusion: From the results, it was suggested that the immune response is enhanced due to antioxidative activity caused by the EF-2001 and anti-tumor activity by NK cells and TNF-α.