Objective Finding out the kinds and activities in protease of brain,heart,lung,kidney,eyes,skin and muscle of Andrias davidianus. Methods Using protease returned electrophoresis technique(G-PAGE). Results 1.Activity of proteases in brain was weak at pH 4.5,and showed no activity at pH 7.0 and pH 9.5;2.Proteases of heart and lung had activities at pH 4.5 and pH 7.0;3.Activity of kidney proteases was strong at pH 4.5 and stronger at pH 7.0,and kinds of proteases were more at pH 7.0 than at pH 4.5;4.Proteases in eyes had no activity at pH 4.5 and pH 9.5;5.Activity of proteases in muscle was very strong at pH 7.0 and pH 9.5,and kinds of proteases were more at pH 7.0 than at pH 9.5;6.Activity of skin proteases was similar to that of muscle,but the former was weaker than the later. Conclusions Among the seven kinds of tissues and organs of Andrias davidianus,kinds and activities of kidney and muscle proteases were stronger and more than others;and the eyes showed almost no protease activity.The proteases-activity optimal pH of brain was acidic;The proteases-activity optimal pH of heart,lung and kidney was acid of neutral;and the proteases-activity optimal pH of skin and muscle was neutral.