Abstract: The present invention is directed to a glycol chitosan derivative having a hydrophobic substituent, to a method for preparing the glycol chitosan derivative, and to a use of the glycol chitosan derivative. In particular, the glycol chitosan derivative has a structure where an amine group at the 2-position is partially substituted with an acetyl group and a hydrophobic group R and is utilized in medical, bio, electric and other fields, by virtue of its thermo-sensitive characteristics of causing sol-gel transition at a predetermined temperature.