Despite extensive progress in the production of anti-cancer drugs, attention to some natural products, such as Melittin from honey bee venom, is growing. Some studies have shown that this product has anti-cancer properties. To evaluate the effects of Melittin on function breast cancer indicators in inbred Balb/c mice as well as its effects on liver and renal enzymes, 4T1 cell lines were purchased from Pasteur Institute and were cultured and the induction of breast cancer was performed in the breast area of mice. The 20-day treatment period was performed in 9 groups (including 6, 3, 1mg/kg body weight of Melittin, doxorubicin, cisplatin, PBS, DMSO, healthy control, negative control). At the end of the course, animal blood samples were taken then liver and renal biomarkers were measured after serum isolation. From the induced tumor tissue sample, after fixation in formalin, the immunohistochemical tissue slide was prepared and studied for KI67 expression. Results showed that renal (BUN) and liver biochemical markers (AST, ALT as well as ALP) had no significant changes in melittin treated group at the dose of 6 mg/kg compared to control group. The results of histopathology showed a decrease in tumor cell invasion in Melittin therapeutic groups, which was more evident at a dose of 6 mg/kg. In immunohistochemistry, KI67 expression did not show a significant change in all groups. The results of this study show the beneficial effect of melittin in preventing the growth of tumor cells without injuring the liver and kidneys compared to other common drugs.