Gluconic acid is one of interesting chemical products in industries such as detergents, leather, photographic, textile, and especially in food and pharmaceutical industries.Fermentation is an advantageous process to produce gluconic acid.Mathematical modeling is important in the design and operation of fermentation process.In fact, kinetic data must be available for modeling.The kinetic parameters of gluconic acid production by Aspergillus niger in batch culture was studied in this research at initial substrate concentration of 150, 200 and 250 g/L.