In order to ensure safe operation of secondary cycle and reliability of steam generator, it is of great significance to reduce corrosion of equipment & piping of the cycle in nuclear power plant. With the deepening research on organic amines and the continuous accumulation of operation experience, the industry realized that the metal corrosion in the cycle during plant operation depends mainly on the pH at the operating temperature of locations of the cycle, i.e. pHt. To improve pHt at the locations of the cycle, performance characteristics of the main organic amines and their combinations are analyzed in this paper. Combined with the application experience and actual effects of organic amines at home and abroad, the application strategy of the main organic amines and their combinations are discussed and proposed, and the improvement suggestions are put forward with regard to current amine application status of the secondary cycle in China. Selections of amine or its combination should calculate the pHt at various locations to meet anti-corrosion requirements and evaluate effects on service life of resin beds in the system. Ethanolamine with stronger basicity and low volatility is suitably used in plant in which corrosion product is mainly from drain systems and condensate polishers are in continuous operation. 3-methoxyypropyl with strong basicity and moderate volatility can be used in most plants. Morpholine with weaker basicity and moderate volatility is suitably used in plants in which polishers are not in continuous operations. Dimethylamine and ammonia are suitably used with other amines because of their high volatility. Amine mixture application appears advantages on aspects of the anti-corrosion and service life of the resin beds.