Glutamine is the most abundant free amino acid in human and other mammalian plasma, which plays an important role in the organism metabolism. Glutamine is unstable in acid and heating conditions, but the small peptides containing glutamine are very stable, which has a high value in use. The physiological functions and application of glutamine and its binding peptide, the advantages of gln-bound peptide, the method of production, and detection of glutamine were systematically described.