Trypsin inhibitors occur in a wide range of foods, they have been studied extensively in plants such as soybean (Glycinemax) as the majority of species are considered as important food sources. Selected soybeans were subjected to various treatments including microwave heating, supercritical fluid CO2 de-fatting, ultrasound incubating by different treat time (5min-120min) to determine the effect on soybean trypsin inhibitor (STI) activities compared to the non-treatment. The results indicated that microwave reduced trypsin inhibitors ranged from 20.57±1.40 TIU/mg to 14.60±1.48 TIU/mg compared to the control (21.44±1.04 TIU/mg) respectively (p<0.05). The inactivation of STI activities by ultrasound ranged from 28.47±0.16 TIU/mg to 19.86±0.78 TIU/mg compared to the control (28.87±0.18 TIU/mg) respectively (p<0.05). While the observed STI activities by supercritical CO2 de-fatting was not significant compared to the control. This study signifies the effective potential of inactivation of trypsin inhibitor by several applicable treatments which might be benefit in the food manufacture and livestock feeding industry.