The present invention discloses a material having cross-linking structures. This material comprises a modified substrate containing polysaccharide and a plurality of bridges formed on the modified substrate. Moreover, the bridges bond to the polysaccharide and are self-bonded, so as to form the cross-linking structures, wherein the bridges are formed by a cross-linking agent. Furthermore, this invention also discloses a method for forming a membrane having cross-linking structures, wherein the method comprises a dissolution process, a mixing process and a membrane fabricating process.