Abstract: Major acute phase protein （MAP） is one of the acute phase reactive proteins synthetized in liver， is a new plasma glycoprotein of 120 kDa belonging to inter-α-trypsin inhibitor （ITI） family. With close relation to animal nutrition and health， MAP can provide valuable diagnostic information about animal diseases and severity. Since muscular catabolism is associated to acute phase process， the determination of serum MAP concentration could be an effective parameter in meat inspection and animal welfare. The paper summarized the MAP classification， structural feature and synthetic process， also put emphasis on its application value in animal production field.

Key words: MAP, acute phase reactive protein, inter-α-trypsin inhibitor, animal health