The rapid population growth in Beijing exacerbates the contradiction between social and economic development and water resource shortage. The provision of sufficient and safe drinking water with reasonable pressure to local residents is the primary goal for Beijing Waterworks Group. The South-to-North Water Diversion Project is valuable to alleviate the water resource crisis in Beijing; however, it is of more importance to minimize water loss in distribution systems and to avoid water waste in daily life for residents. Beijing Waterworks Group has long dedicated to decreasing water loss by delicate management of water distribution systems, and the understanding of water loss composition is principal to optimize water-loss-control strategy. This paper analyzed the non-revenue water (NRW) composition in Beijing and the measurements taken to control the NRW. The results showed that Beijing Waterworks Group had made much progress in the NRW control.