Spirulina (family Microcoleaceae) is a cyanobacterium formerly known as algae. Spirulina is highly valued in the animal feed, poultry and aquaculture industries, cosmetics and health care industries, as a source of energy and wastewater treatment. Spirulina is a rich source of protein, vitamins, minerals, fatty acids and pigments. These carotenoid pigments and phycobiliproteins (allophycocyanin, phycoerythrin and phycocyanin) have high commercial value. The pigment content depends on environmental conditions such as light intensity and light quality. In this study, the effect of light intensities (35, 55 and 75 μmol photons/m2s) on the biomass, protein, phycobiliprotein pigments and photosynthesis of Spirulina was investigated using a completely randomized design. The results showed that the best result was at a light intensity of 55 μmol photons/m2s in the production of phycobilin pigments, chlorophylls and pheophytin. While the highest protein and carotenoid pigments were produced at a light intensity of 75 μmol photons/m2s. Both light intensities of 55 and 75 μmol photons/m2s were suitable for biomass production, but the light intensity of 35 μmol photons/m2s was not sufficient for biomass and metabolite production in the cyanobacterium Spirulina. This study showed that different light intensities can have different effects on the biological factors of cyanobacteria.