In general, inlet temperature of cooling sea water for steam turbine condenser is about $25^{circ}C$ and outlet temperature is about $60^{circ}C$. For oil cooler, outlet temperature is about $40^{circ}C$. Therefore corrosion heavily depends on the temperature of the coolant of a heat exchanger system. It is necessary to set the temperature of the cooling water to have maximum heat transfer efficiency. This paper was studied on the effect of temperature on SCC of Al-brass which is used as a tube material of vessel heat exchanger in $3.5\%$ NaCl + $0.1\%;NH_4OH$ solution under flow by constant displacement tester. Based on the test results, the behavior of polarization characteristic, stress corrosion crack popagation and dezincification characteristic of Al-brass was investigated.