Alkaline proteases are commercially important enzymes due to its broad range applications. Intestines from Cyprinus carpio L., which is an important fish in the Brazilian aquaculture, present a high amount of proteases; thus their intestine are proposed in this work as a source of such molecules. The aim of this research was to extract and partially purify proteolytic enzymes from C. Carpio intestine as well as to characterize some of its physico-chemical properties. Protease compatibility with surfactants and oxidants was also studied. The crude extract was submitted to a partial purification by ethanol precipitation. The fraction 30-70% ethanol presented the highest proteolytic activity and was submitted to further studies. The proteolytic activity of this fraction was assayed at different temperatures and pH. Temperature and pH stability experiments were also carried out. Different concentrations of commercially available detergents, surfactants and hydrogen peroxide were used to test the compatibility of these proteases. The fraction containing 30-70% of ethanol saturation showed higher recovery (142.4%) and specific activity (67.4 U/mg protein) when compared to the crude extract. The optimal temperature and pH were found to be 50ºC and 11.0, respectively. The proteases were stable in a pH range of 6.5 – 12.0. The enzymatic activity was strongly activated by non-ionic commercially available surfactants (Tween 20 and Tween 80) and retained more than 80% and 60% of their initial proteolytic activity at 40ºC for 1 hour in the presence of the ionic surfactants sodium cholate and saponin, respectively. In addition to that almost 50% of enzymatic activity was retained in the presence of 5% (v/v) of hydrogen peroxide at 40ºC after 75 min of incubation. The high proteolytic activity of the proteases at extreme temperatures and alkaline pH together with its stability in the presence of the surfactants and oxidants tested indicate that these alkaline proteases can well be used in detergent formulations.