Okara is a byproduct from the soymilk process and it is rich in proteins, fatty acids and dietary fibers. It uses for animal feed and human food. However, it have anti-nutrition factor such as trypsin inhibitor. Trysin inhibitor in soymilk classified into 2 major; Kunitz trypsin inhibitor (KTI) and Bowman-Birk inhibitor (BBI). Pancreatic enzyme secretion and pancreas size were increased from the effect of trypsin inhibitor activity. Thus, the factor to eliminate trypsin inhibitor activity were interested. NaCl could accelerate trypsin inhibitors inactivation. Moreover, the temperature range (50-70°C) were studied. These temperature might not be high enough to significantly change trypsin inhibitor. Bowman-Birk inhibitor was more heat-stable than Kunitz trypsin inhibitor. The result from the experiment showed that, trypsin inhibitor reduces protein digestibility, but has limited effect on the size of pancreas in pigs.