In this paper,the contents and rheological properities of gum from seeds of Gleditsia sinensis Lam.were discussed.It is determined that the seeds of G.sinensis contain 15.38% protein.The endosperm is about 37.8% of the seed contents.Analysis by GC,PC,IR,HNMR shows that endosperm contains 68.6% galactomannan.The propoction of galactose to mannose is 1∶2.5.The chemical structure of the main chain is β(1,4)linked Dmannopyranosyl residues,while the branch chain is α(1,6)linked Dgalactopyranosyl residues in.The viscosity of 1% concentration G.sinensis gum is 274 mPa·s(30 ℃,170 s-1).G.sinensis gum can be a highly efficient waterthickening agents.The viscosity increases with the rising of concentration,and decreases slowly with the reducing of pH.Water solution of G.sinensis gum is nonnewton fluid. 