Biomass concentrations of Scenedesmus sp. with variation of light intensities and nitrogen sources were investigated. At the end of the cultivation period, maximum biomass concentration was recorded under nitrogen deficiency and low illumination (1,000 lux), which was about 3-fold higher than other conditions. However, applying high illumination (6,500 lux) did not significantly boost the biomass concentration. At desired illumination, the fact was revealed that the excessive amount of nitrogen source may waste the chemical and financial resources. The presence of C16:0, C18:1, C18: 2, and C18: 3 as the major constituents (81.84% of the algal oil) makes Scenedesmus sp. biomass a suitable feedstock for biodiesel production.