Physical and chemical properties of gelatin extracted from grass carp fish scales were determined,and the comparative study between the properties of fish scale gelatin and mammalian gelatin were also analyzed.The results indicated that amino acid composition of grass carp fish scales gelatin were rich in praline,hydroproline,glycine and alanine,but the contents of amino acids and hydrophobic acids were lower compared with the mammal gelatin.The α and β-component(α-chain and α-chain dimers) contributed the most of the total molecular weight of the gelatin,which was about 88%.The gelling point and the melting point were 20.8℃ and 26.9℃,lower than the mammal gelatin.The intrinsic viscosity and the surface hydrophobic index(S0) were 0.73 and 259.59,respectively.The high gel strength and speed of the gelatin formation had a good relationship with α and β-components.The gel point and the melting point were associated with the content of amino acids.The liner relationship was existed between the intrinsic viscosity and the α-component(α1+α2) of the gelatin from different resources.