In the present study, the experiments were conducted during the period from June to October 2019 (20-weeks) to evaluate the effect of Biofloc technology (BFT) on mono sex Nile tilapia, Oreochromis niloticus fingerlings. It was focused on water quality, growth parameters, hepatosomatic index (HIS),  spleenosomatic index (SSI), Hematology, and biochemistry. Triplicated treatments were designed, two Biofloc treatments with two fish densities (12 &16 fish/200 L tank) vas two control groups. All treatments were fed with 3% of body weight in two equally divided meals. Rice brane and Molasse (1:1) were added as a carbon source to Biofloc treatments twice daily after one hour of main meals. Results indicated that total ammonia-N and Nitrite-N were significantly decreased at Biofloc treatments. Biofloc treatments showed significantly high average final body weight, better feed conversion ratio (FCR), and one-ninth water consumption. Biofloc addition had generally no significant difference of hematology, biochemistry, and hepatosomatic index (HSI), while spleenosomatic index (SSI) was significantly increased at high density only. It could be concluded that Biofloc treatments improve water parameters stability and fish growth performance while it decreased water consumption. High density (16 fish/200 L) is a more yield productive treatment.