Interest in protection against solar ultraviolet radiation (UVR) among the general public in the world has been increasing steadily. Poly(ethylene terephthalate) (PET) was blended with UVR-protection agents and was spun into modified fibers to provide the property of UVR protection. Investigation of this property using a UV spectrophotometer showed that the modified PET fabrics could be resistant to UVR more than 90% in the UV-B band. The treatment of aqueous alkali on the surface of the fibers to improve the comfortable feel had little influence on the property of UVR protection. Scanning electron microscopy was employed to observe the surface morphology of the fibers. Also, the modified fibers had good heat insulation property and the mechanical properties of the fibers were measured. (C) 2003 Wiley Periodicals, Inc.