Objective: To study the activity of statins and alloxan induced oxidative stress and oxidative defense system in rats. Method and Materials: Either sex of Wistar rats were used for studying the activity of statins (Atorvastatin) and oxidative stress is induced by the induction of alloxan (100mg/kg) and statins acts as antioxidants which suppressed the oxidative stress. Animals were divided into five groups and each groups having six animals. Freshly prepared alloxan (100 mg/kg) i.p. were given to third group at first day and forth group at first day then followed by statin (30mg/kg), orally, up to seven day and fifth group at last day of treatment to produced oxidative stress. And investigate the defense mechanism of statins which suppressed the oxidative stress produced by the alloxan. Result: With the help of investigation of biochemical parameters of different groups of animals we found out that atorvastatin showed significantly suppressed the oxidative stress produced by the alloxan and impaired the oxidative defense system in rats. Conclusion: From the investigation it was found that alloxan produced the oxidative stress and statins impaired the oxidative defense system in rats.