Objective To evaluate in-vitro antioxidant, anti-inflammatory and antitumor abilities against human breast adenocarcinoma (MCF7) and human prostate cancer (PC3) as well as the suppressor effect of bacterial exopolysaccharide (BAEPS) on Ehrlich ascites carcinoma (EAC). Methods In-vitro antioxidants characters of BAEPS were determined using various methods, while anti-inflammatory activity was estimated against cyclooxygenase (COX-1 and COX-2). In-vitro study, anticancer against MCF7 and PC3 were assessed by the mitochondrial dependent reduction of yellow MTT. In in-vivo study against EAC progression, mice were inoculated with EAC cells and then were orally administered BAEPS at 200 mg/kg after 24 h (equals to 0.10 of determined LD