The prevalence of cancer is increasing nowadays. In Indonesia, the prevalency of cancer is 1,4% out of 1000 people. Cancer is mainly caused by two factors; genetic and environmental, one of them being is a carcinogenic agent benzopyrene. Physical exercise can decrease blood glucose and fatty acid levels within the blood but its effect on cancer prevention, especially on caspase-3 expression, is still unknown. This study examines the expression of caspase-3 produced by moderate exercise in preventing the formation of transform cell epithelial of the oral squamous cell. 18 mice were divided into three study groups; control group 1 (K1) not given any physical exercise and benzopyrene, control group 2 (K2) not given any physical exercise but induced with 0,08 mg benzopyrene, treatment group (P) were given physical exercise in moderate intensity and induced with 0,08 mg benzopyrene. Buccal mucosa tissue samples were taken and stained for immunohistochemistry and examined under a light microscope at 400x at 10 different angles. The mean of caspase-3 expression was found highest in group P (13.33), meanwhile in group K1 and K2 were 3.00 and 8.33, respectively. There was significant difference of caspase-3 expression between the groups (p = 0.000) Conclusion: Moderate exercise could increase caspase-3 expression in preventing the formation of the transform cell epithelial of the oral squamous cell
