Abstract: Nano-scale Zero-Valent Iron (NZVI) particle is a kind of iron particle with diameter ranging between 1 to 100 nm. Its specific surface and reactivity are much higher than normal iron fillings and iron power. It can be filled into underground heavy polluted area directly to form a high-efficient in situ reactive zone, and remediate the contaminated groundwater in a versatile, high efficient and lowcost way. NZVI not only can degrade all kinds of halogenated hydrocarbons, but also can degrade some other kinds of organic pollutants, heavy metal irons and some inorganic anions. NZVI groundwater remediation technology has already been applied in developed countries, and is expanded quickly. Effects by in situ factors on the remediation effects of NZVI are significant research highlights, the efficient scattering and transport of NZVI in aquifer are the main point for scientists to breakthrough in the future.