Inflammatory factors have a major role in developing different types of cancer and cancer related cachexia. In contrast, training can exert anti-inflammatory effects. Therefore, the aim of the present study was to investigate the effect of 4 weeks of continuous and interval training on levels of MCP-1 in serum and muscular tissue of female mice with breast cancer. 32 female balb/c mice were randomly divided into four groups: control, tumor control, continuous training + tumor and interval training + tumor. In order to induce breast tumor, MC4-L2 cell line was injected into mice. Moderate intensity continuous and interval training were conducted for four weeks and five sessions per week. 48 hours after the last training session, blood samples were collected and the gastrocnemius muscle was separated to determine the levels of MCP-1 by ELIZA method. Moreover, tumor volume was measured by digital caliper. Data were analyzed by SPSS software and one-way analysis of variance test and Tukey post hoc test. Results indicated significant decrease of serum MCP-1 levels in continuous and interval training groups and also significant decrease of MCP-1 in gastrocnemius muscle tissue of interval training group compared with tumor control group (P<0.05). In addition, tumor volume indicated significant decrease in both training groups compared with tumor control group (P<0.05), but continuous and interval training did not affect gastrocnemius muscle weight (P>0.05). With regard to the present findings, the positive role of training in tumorous mice may be exerted partly by mediating inflammatory factors such as MCP-1.