The present study shows that the dietary protein level markedly affects the growth; feed utilization,and physiological status of Nile tilapa in all weight ciasseh. The optimum dietary protein required for Nile tilapia is weight dependant;fry tilapia(-0.5 g ) required the 45%-CP diet for optimal growth; whereas, fingerling (-20 g) and advancedjuvenile (-40g) performed optimally with the 35%-CP diet. EI-sayed and Teshima(1991) found similar results in terms of the protein requirement of Nile tilapia;with values ranging between 20% and 56%CP.The studies of Balarin and Haller (1982) showed that fry of tilapia required a diet ranging between 35 and 50%CP, and 5-25 g fish between 25 and 35% CP. Tacon (1987) reported dietary protein levels varying from 42% for fry to 35% for growing adults of omnivorous fish species. Our results show a nore accurate description of dietary CP needs for different life history changes,as we tested the possible variations within these ranges(25-45%) . Variataons in dietary CP needs at different life history stages. EI-sayed ana Teshina(1991) found tnat dietary protein requirements decreased with increasing fish weight and age.Both in fingerling and advanced juvenile of Nile tilapia,excess protein could not be utilized efficiently and might have been used for energy.