Provided is a method for conveniently and efficiently producing a polymer compound having a superior thickening effect, having as starting materials a plant that conventionally has been disposed of as waste, and having superior safety from the starting materials and a low environmental impact. The method for producing a polymer compound is characterized by obtaining a polymer compound fixim Corchorus capsularis L . and/or Corchorus aestuans L . and having a shear viscosity of at least 0.2 Pa s at a shear speed of 10 (1/s) and at 25�C of an aqueous solution having a concentration of 1 wt%, by means of the below mentioned steps: ste 1) alkali extraction step 2) purification.
