Combined light sources of red-blue light, red-green light and blue-green light were also applied to Spirulina, and it was found that the maximum dry matter contents of Spirulina were 1.518 g/L, 1.389 g/L and 1.232 g/L for red-blue light, red-green light and blue-green light respectively. Therefore, the Spirulina exposed to red-blue light attained the highest growth rate with the corresponding dry matter content increasing by 76.72% when compared with the control group.