THIAMINE and pyridoxine were investigated for their capacity to .alleviate oxidative damage by copper stress on a local alga (C. vulgaris). Lower levels of Cu+2 induced a slight stimulation in growth criteria (growth rate & dry weight), photosynthetic pigments (0.5µM) and O2-evolution (0.5, 10 µM) of C. vulgaris which was inhibited by high Cu+2 concentrations. In contrast, O2-uptake was retarded at the lower Cu+2 levels then significantly increased by increasing the Cu+2 in algal cultures. Proline, MDA contents, and antioxidant enzyme activity of C. vulgaris markedly increased under Cu+2 stress. On the other hand, the addition of thiamine or pyridoxine alleviated the oxidative damage of Cu+2 on C. vulgaris growth and enhanced growth, pigment contents, O2- evolution, and antioxidant enzyme activity in the algal cultures compared to reference controls. While O2-uptake, proline content, and lipid peroxidation levels were decreased, thiamine or pyridoxine scavenger systems might be important for supporting the ability of C. vulgaris to resist copper toxicity