Abstract: In this study two local isolates Aspergillus japonicus and Aspergillus oryzae were investigated for tannase production on synthetic medium containing tannic acid as sole carbon source. Optimizations of intracellular tannase production at different culture conditions using batch and submerged fermentation techniques were studied. The highest levels of tannase were detected after 2 and 3 days from A. japonicus and A. oryzae, respectively. A. japonicus degrade tannins 3.79 times faster than A. oryzae. Tannase production was optimum 2.0% tannic acid, 0.3% NH4Cl, 0.1% CaCl2 and pH 4.5. Addition of glucose adversely affected the rate of enzyme production by A. japonicus; however, A. oryzae tannase was stimulated at lower glucose levels (0.05-0.4%). Extract of 3% of China green tea was suitable for tannase production compared with other tannins. Finally, parametric optimization of tannase yielded 1.77 and 1.70 fold increase in case of A. oryzae and A. japonicus, respectively. Biodegradation of tannic acid during the fermentation course of A. oryzae indicated that, di-gallolyglucose, tri-gallolyglucose and tetra-galloylglucose appeared in the culture filtrates during the first 12 h. However, mono-gallolyglucose was the end product after 6 days.