The influences of hydrophilic treatment of the PET fabric on soiling and detergency of triolein were studied. The amounts of residual triolein were determined by radiotracer analysis, and distributions of the unsaturated oils on the fabric were evaluated by backscattered electron images. The removal of triolein was increased when the PET fabrics were treated. SRP pretreatment was more effective on the oily soil removal than the of addition of SRP in the detergent. The oily soil of triolein only was packed between the fibers, but mixed soil was distributed around the fibers. When the mixed soil was used, detergent solution could penetrate the continuous interfiber capillaries, this would be one of the reasons that mixed soil was removed rmore extensively.