This study was investigated at the laboratories of Horticultural department, Faculty of Agriculture, Damascus University to measure the changes in oxidative and antioxidative parameters during tomato fruit growth. Hydrogen peroxide (H2O2) and lipid peroxidation (MDA) contents were analysed as indicators of oxidative processes. Results showed that H2O2 content decreased during fruit growth phase and slightly increased during ripening, meanwhile MDA content was found to increase only at the end of fruit ripening. The activities of antioxidant enzymes (SOD, APX, CAT) were modified during fruit growth. Activities of SOD, APX increased during fruit growth phase, meanwhile CAT activity increased during fruit maturation. The level of ascorbate increased during fruit growth. These changes in antioxidant metabolites and enzymes establish that the antioxidant system plays an important role in the both phases of tomato fruit growth.