Abstract: The study was conducted in order to find the protein requirement of bighead catfish (Clarias macrocephalus) fingerling. The initial weight of fish was 6.29 g/ind and raised them in 8 weeks. The experiment was set up with six dietary treatments including six protein levels such as 25%, 30%, 35%, 40%, 45% and 50% with an isoenergy of approximately 4.5 Kcal/g and an isolipidic diets of 8%. Results show that the protein level effected on the survival rate. The 25% protein diet had the lowest survival rate of 67.78% while those in the remaining treatments varied from 91.1% to 100%. The specific growth rates (SGR) of fish were maximal at 3.26% per day in the 45% protein diet and minimal at 1.92% per day in the 25% protein diet. The protein efficiency ratios (PER) decreased as the protein levels in diets increased. The protein content affected significantly by the dietary protein levels. Using the Broken-line method and based on the SGR, the dietary protein requirement for bighead catfish was 46.1%.