Abstract: The white cotton poplin was applied with TiO_2-SiO_2 sol by double-dipdouble-nip method at room temperature,followed by hot water(98～(100 ℃))treatment for 20 min,and then air-dried.The testing of UV transmittance and ultraviolet protection factor(UPF) of the treated fabric showed that its UV screening property improved significantly.The SEM,AFM and XRD were used to characterize the TiO_2 on the cotton fabric.It was observed that the size of anatase TiO_2 on the cotton fabric was about 30 nm.The standard test to washing showed that the nano TiO_2 in-situ growth on the cotton fabric had excellent fastness to washing, and after 10 washing cycles its UV screening property even enhanced instead of decreasing.