Objectives: The object of this study was to observe antitumor, anticachexia and immunomodulatory effects of Shipyeukmiyeugi-eum(SYM) on human breast cancer cell, MCF-7, xenograft Balb/c nu-nu nude mice. Methods: Three different dosages of SYM-125, 250 and 500 mg/kg were orally administered once a day for 28 days from 11 days after tumor cell inoculation, and the changes on the body weights, tumor volume and weights, weights of spleen and popliteal lymph node and epididymal fat, serum IL-6 and IFN-${gamma}$ levels, NK cell and peritoneal macrophage activities, splenic TNF-${alpha}$, IL-$1{eta}$ and IL-10 contents were observed. In addition, histopathological observations of apoptotic cell, spleen, popliteal lymph node and cervical brown adipose were also detected. The results were compared with a potent cytotoxic estrogen receptor antagonist, Tamoxifen 20 mg/kg treated mice. Results: Tumor volumes and weights were decreased without cytotoxic effects on the both MCF-7 and MCF-10A cells as results of all three different dosages of SYM treatment. And weights of body, spleen, popliteal lymph node, epididymal fat, serum IFN-${gamma}$, NK cell, peritoneal macrophage activities, splenic TNF-${alpha}$, IL-$1{eta}$ and IL-10 contents were increased with decrease of serum IL-6. At histopathological observations, apoptotic tumor cells, spleen, popliteal lymph node and cervical brown adipose tissue were increased. That means tumor-related immunosuppress and cachexia were markedly inhibited by SYM treatment as compared with tumor-bearing mice. On the other hand, Tamoxifen showed marked cytotoxic effects against MCF-7 and MCF-10A, decreases of tumor volume and weights, and increases of apoptotic tumor cells and related decreases of tumor cell volumes, but tamoxifen markedly deteriorated the tumor-related immune-suppress and cachexia. Conclusions: The results obtained in this study suggest that SYM showed favorable anticancer effects and anticachexic effects on the MCF-7 cell xenograft through immunomodulatory effects. SYM did not induce any cytotoxic effects against both normal and cancer cells.