The present paper describes a combination device for evaluating natural daylighting and air-cleaning potential of light rods and photocatalytic oxidation in buildings. Light rods and light pipe transfer day-lighting contain with UV light which induced photocatalytic activity at TiO2 for photocatalytic degradation of VOC (Volatile Organic Compounds) and unpleasant odor to improve indoor air quality. The initial device is incorporated with an artificial UV light to evaluate the optimum efficiency results. Then, validate the experimental data from using an artificial UV light to natural day-lighting condition. The results are found that photocatalytic degradation happened both on UV light and natural day-lighting. For the sustainable aspect concerns, natural day-lighting has several benefits of healthy (physical and mental) working environment and energy savings. These results can be further used to study optimum lighting and air purifying contributions of the device and apply to buildings in the future.