Following the previous three successful ABaCAS conferences, the 4th Air Benefit and Cost and Attainment Assessment Conference (ABaCAS 2016) will be held on June 14-16, 2016 in Shanghai, China. This conference is hosted jointly by Shanghai Jiao Tong University, Shanghai Academy of Environmental Sciences and Shanghai Environmental Monitoring Center, and co-organized by Tsinghua University, South China University of Technology, University of Tennessee and Zhejiang University with the support from China Ministry of Environment, U.S. Environmental Protection Agency and Energy Foundation (U.S). The Conference aims at providing a high-level platform for air quality scientists and policy makers from various disciplines to exchange ideas and views on key leading issues related to environment and energy in China, Asia, and all over the world. In addition to the two-day conference (June 15-16), a one-day training workshop (June 14) on the “Air Benefit and Cost and Attainment Assessment System (ABaCAS) will also be provided to air quality managers and scientists of interest with demo and hands-on sessions on cutting-edge air quality management and assessment tools.