The low surface energy of PET fiber makes it inherently hydrophobic.PET nonwoven fabric was treated by gas plasma.The effects of treatment time,power and the discharge distance on the hydroscopicity of the nonwoven fabric were determined through experiments.The results indicated that this treatment can improve the hydroscopicity of PET nonwoven fabric remarkably.As power increases,the moisture content increases to the top value then decreases a little, and longer time of treatment also improves the moisture content.The discharge distance being about 1 mm can generate uniform plasma which renders the fabric an even treatment.