The freshwater green alga Chlorococcum sp. grew on NH_4^{+},{;}NO_3^{-}$, urea, yeast extract, and peptone as the nitrogen source showing similar pattens of growth and secondary carotenoid (SC) production. However, the most suitable nitrogen source for the induction fo SC was urea. The dffects of nutrient levels (urea, phosphate, sulfate, ferrous iron, and salt) on growth and SC production were stydied by varying the concentration of each nutrient in batch cultures. High biomass production was achieved in cultures containing 20-28 mM urea, 4.8-10 mM phosphate, 1.6 mM sulfate, 70 mM phosphate, 1.6 mM sulfate, 170 mM NACl, and $50{;}mu extrm{M}$ iron. The optimum concentrations of nutrients for biomass and for the SC accumulation in biomass were evaluated and the two media for achieving high biomass production and SC production were thus developed. The extent to which each parameter to stimulate the formation of SC in the alga were varied and the potentially improned SC prodution by manipulating the nutrient levels in the modified media were descussed.