Abstract: The general corrosion of A508Ⅲ and A106Gr.B in pressurized water reactor secondary circuit was studied by means of long-term immersion in three alkalizers, such as ethanolamine (ETA)+dimethylamine (DMA) mixed alkalizer, ETA and ammonia (NH₃·H₂O). And scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES) were used for demonstrating the asprepared oxide films. The results show that the corrosion rate of A508Ⅲ samples is 0.15 mg/(dm²·h) after 2 000 h immersion in NH₃·H₂O, but that is 0.087 mg/(dm²·h) in ETA+DMA mixed alkalizer, just dropped by 42% compared with in NH₃·H₂O. In similar, the general corrosion rate of A106Gr.B in ETA+DMA also drops by 29.01% compared with in NH₃·H₂O, demonstrating that samples display better corrosion inhibition effect in ETA+DMA. The XPS and SEM results show that oxide film is much thinner and denser mainly composed of Fe and O. A little N element can be found in the film formed in ETA+DMA, illustrating that amines involve in the formation of oxide film. The improved corrosion resistance can be attributed to the less volatile of DMA at high temperature, which improved pH value of liquid, thus inhibited iron’s oxide reaction. On the other hand, the adsorbed amine molecules on the surface of samples reduce the activation energy of the metal oxidation reaction partly. Mixed alkalizer exhibits superior compatibility with materials in secondary circuit, which makes good sense for improvement in water chemistry in secondary circuit.