Engineering nano-materials ＆ their impact on human health or environmental security constitute a newly emerging R＆D hot spot and a key problem now urgently waiting for its solution in supporting the sustainability of China＇s nano-science and related technology development. At present, water bodies in Chinese cities have been seriously polluted by metallic nano-particles （MNPs） while related monitoring data are found woefully lacking throughout the country. Based on the above understanding, this article gives a round-up explanation on distributive characteristics of MNPs in the river mouths or water bodies of Chinese cities, their ecological hazards as well as our research in this regard, providing some inspiring ideas and data for control over this scourge. In addition, our exploration probes the discharge traits of MNPs themselves and the mechanism underlying its impact on water pollution.