The effects of different factors on producing tannase have beenstudied,such as different carbon sources ,carbon source ratio,different nitrogen sources,nitrogen source ratio and initial pH value. The optimal mixture and the optimal culture conditions of liquid state fermentation to produce tannase have been obtained by making orthogonal tests. The results showed that the optimal mixture was soyabean meal (0.67%),tannin acid (1.2%) wheat flour (0.3%),NH4NO3(0.05%) ,KCl (0.05%),MgSO47H2O (0.05%),FeSO4 (0.001%),K2HPO4 (0.03%),and pH6.0.The tannin acid,the combination of soyabean meal and NH4NO3,a...