Abstract: AIM:To observe myocardial tissue injury caused by a self-made, small animal quantitative trauma device. METHODS: Forty rats were randomly divided equally into two groups: control group (n=20) and trauma group (n=20). Rats of the trauma group were anesthetized with pentobarbital sodium (40 mg/kg), individually placed on a self-made small animal quantitative trauma device and were traumatized as the wheel rotated (200 revolutions (r) at a rate of 40 r/min). Measures were taken to observe the pathological changes of myocardial tissue. RESULTS: Compared with those in control group, the apoptotic index of the myocardial cells was elevated (P<0.01). Activity of caspase-3, expression of both iNOS and NADPH oxidase, and production of both NO and ·O-2 (superoxide anion) were also increased in the trauma group (all P<0.01). CONCLUSION: Mechanical trauma may induce significant oxidative stress and apoptosis in rat myocardial tissues by using a self-made, small animal quantitative trauma device.