The microalgae are unicellular microorganism which is the particular place and special role in aquatic nutrition. Awareness of optimal conditions the production of these organisms is necessary. Therefore, in this study, the effects of different light intensities are examined (1000, 2000 and 5000 lux) on the growth Tetraselmis chuii. The results showed that the light intensity of 5,000 lux on the seventh day growth rate and cell density cultivation of Tetraselmis chuii was achieved with a 138.31×104±53.64×103 cells per ml, but the light intensity of 2000 lux was reached most of the cell density on a ninth day with of 137.50×104±38.18×103 cells per ml as compared to 1000 and 5000 lux light intensity was significantly of the highest cell density (P <0.05). However, the lowest density of microalgae cells for the treatment of light intensity of 1000 lux with 56.00×104±43.94×103 by the tenth day. Hence, it can be concluded that with increasing light intensity Tetraselmis chuii was reached their maximum growth and density in a shorter time.