Annual production output of poly (ethylene terephthalate)(PET) fiber has been over 15 million tons in China due to its good mechanical properties and processability,but the shortage of hydrophilic group of PET has imposed many limitations to further extend its application.The PET fabrics were grafted with polyacrylic acid in inverse microemulsion after low pressure plasma treatment,and the microstructure and properties of the grafted fabrics were investigated with infrared spectroscopy, scanning electron microscope (SEM),hydrophilic and mechanical tests.The grafting yield was increased with the grafting time.The grafting polymer was in the granular form with its particle size ranging from a few micrometers to a dozen of micrometers,normally smaller than the fiber diameter.The moisture regain and water uptake increased while the air permeability of the grafted fabrics decreased with the increase of grafting yield.The bending rigidity and tensile properties show slightly complicated behaviors with grafting yield.The inverse emulsion grafting technique can be used to control the grafting polymer architecture.