Kinetic effects of UV irradiation on poly(vinyl butyral) (PVB)/naiio-TiO2 films were studied under different operating conditions at room temperature. Samples of the films were illuminated for different times in a UV chamber. The residual properties of the films before and after the UV exposure were analyzed to evaluate the photocatalytic effects. Thermogravimetric analyzer (TGA) was used to determine the residual quantities of the samples left after the exposure with different periods of time, while the carbonaceous residues were analyzed by element analysis (EA) to estimate the carbon content. The kinetic parameter of the photocatalytic reaction was determined from the residual mass of the treated samples. Results show that PVB was photodegraded according to the analytical data of the residual mass. chemical structures, and surface images of the films. TiO2 composition of the samples is the most influential factor to affect the photodegradation rate. In addition, the irradiation distance or light intensity, type of substrate, and film thickness were also factors that influenced the degradation rate.