As one of the most widely used nanomaterials, more titanium dioxide nanoparticles (TiO2-NPs) have been found in natural water.Their potential risk is largely dependent on the aggregation states.The effects of natural organic matters on the stability and mobility of TiO2-NPs has been widely investigated, however, studies on the effects of synthetic organic compounds (SOC) which is one of the most important pollutants in natural water are deficient.