Abstract: To research the characteristics of endogenous proteases from abalone( Haliotis Discus Hannai Ino)viscera.The effects of p H,temperature,metal ions and specific protease inhibitors on endogenous proteases activity were investigated. The results showed that the content of endogenous proteases was 125.10 mg / m L. The protease activity could be increased at low concentrations( 0 ~ 1.36 mol / L) of Na~+,and the activity of protease tended to be stable under the presence of Ca~(2+),however,high concentrations of Na~+,Cu~(2+) and Zn~(2+) significantly inhibited the activity of protease.The optimum working p H of endogenous proteases were located at about 4 and 7at which condition protease showed high activity and good thermal stability. Endogenous proteases could be inhibited by Pepstain,PMSF( phenyl- methyl- sulphonyl- fluoride),SBTI( soybean trypsin inhibitor) and TPCK( tosyl- phenylalanine chloromethyl- ketone).The research can provide theoretical basis for shortening the traditional fermentation time of abalone sauce.