Abstract: The general corrosion behaviors of Inconel690 for steam generator (SG) tube were studied in the simulation environment of secondary loop of pressurized water reactor (PWR) with ethanolamine (ETA) and ammonia (NH₃) separately. After exposed to the simulation environment with ETA for 5 000 hours, the weight loss rate of Inconel690 is 0.21 mg/(m²•h). But for the tests under the NH₃ environment after 5 000 hours, the weight loss rate of Inconel690 is 0.50 mg/(m²•h). In addition, there is more chromium in the oxidation film formed in the simulation environment with ETA, and the oxidation film is more protective. The results show that Inconel690 is more resistant to general corrosion in the environment with ETA than that in the environment with NH₃.