The impact of non-agricultural ammonia (NH3) emissions on urban ambient particles and human health is a new environmental concern.Even though future reductions in the emissions of NOx and SO2 are expected to improve air quality,meeting China’s PM2.5 standards is proving a challenge in the absence of NH3 control.The starting point for finding credible solutions is to comprehensively establish a city-specific Non-agricultural Ammonia Emission Inventory (NAEI) and identify the biggest source where efforts can be directed to deliver the largest impact.In this paper we present a NAEI of 113 national key cities targeted on environmental protection in China in 2010,which for the first time covers NH3 emissions from pets,infants,smokers,green land,and household products.The NAEI reveals the relative scale of seven NH3 sources and highlights that traffic and fuel combustion should be the focus of future controls.Moreover,the results suggest that the non-agricultural sources of NH3 emissions potentially have a significant impact on PM formation in urban China.Therefore,in addition to current SO2 and NOx controls,China needs to put more scientific,technical,and legal attention on controlling non-agricultural NH3 emissions in the future.