Light is considered as a key ecological factor affecting the growth, development and survival of aquatic organisms. This study evaluated the effects of light intensity on growth and survival rate of freshwater prawn larvae (Macrobrachium rosenbergii) reared in biofloc system at 17.5 of C/N ratio. The experiment consisted of five light intensities of 1,000 lux (T1), 10,000 lux (T2), 20,000 lux (T3), 30,000 lux (T4) and natural light (control) in triplicate. The larvae were stocked in 250-L tanks at 12‰ of water salinity and 60 inds L-1 of density. The rearing systems were exposed to light at 12Dark:12Light of photoperiod and lasted for 32 days. The results showed that the water quality, microbial counts, and floc performance were maintained in suitable ranges for development of M. rosenbergii larvae. Floc contained 29.37-30% of protein, 2.37-2.63% of lipid and 28.1-28.46% of ash. After 32 days, the T3 treatment (20,000 lux) demonstrated the most efficiency in larval metamorphosis, growth (10.94 mm), survival (58.23%) and productivity (34,919 ind m-3 ) while the larvae at 1,000 light lux showed the lowest values (p < 0.05). It suggested that application of biofloc technology with 20,000 exposed light lux for freshwater prawn larvae could help to improve water quality and larval performance