Abstract: The water-soluble polyester(WSP) was synthesized from PTA,EG and SIPE by copolycondensation.The rheological behavior of self-produced WSP was studied with Rosand RH7 capillary rheometer.The results show that the shear viscosity of WSP declines and the non-Newton index increases with rising of the temperature.Under the same conditions,the shear viscosity of WSP is higher than that of PET.The shear viscosity of WSP is more sensitive to shear rate than PET.The viscoflow activation energy declines with increase of shear rate.The influence of the third monomer SIPE and temperature on rheological behavior was also investigated.