Background: Inulin is a natural storage carbohydrate has benefits effect largely related to its chemical structure as it has antitumor and antioxidant activity. Objectives: This study aims to investigate the antitumor & antioxidant activities of inulin against Ehrlich Ascites Carcinoma (EAC) in female mice, also study the effects of inulin on liver and kidney tissues. Materials & Methods: forty female Swiss albino mice were divided into four groups each group include ten mice: Group 1 “negative control group" mice were injected with sterile saline, group 2 “Positive control group" mice injected with EAC, group 3 “Therapeutic group" mice injected with EAC then inulin, and group 4 “Preventive group" in which mice were injected with inulin then EAC. The most effective dose of inulin was determined, viability test and life span were performed. Also, antioxidants, liver and kidney functions were measured. Results: inulin was safe compound with the most effective dose (5 mg/kg), inulin treatment showed a significant inhibitory on EAC count and volume in both preventive and therapeutic groups as well as, it recorded a significant reduction in anti-oxidants ( malondialdehyde, total antioxidant capacity, superoxide dismutase, catalase, and reduced glutathione), with slightly changes in liver & kidney tissues. Conclusion: Inulin has strong effect against EAC because of its chemical structure that responsible for its antioxidant activity.