Bromelain is isolated from the stems, leaves and the skin of pineapple by employing modern biologicalextraction technology. It is mainly composed of proteinase and many others contents. Its a ctivity speci-fication is indicated by GDU/g and the maximum activity specificati on can reach up to 3000GDU/g. Bromelain could hydrolis is the protin and health products,food,cosmetics, forage,leather ,industry and so on.Because it has the function of strongly decompositing fibrin and the blood clot, therefore especially is remarkable effect in the medical application.