We cordially invite you to attend the 15th International Congress of Quantum Chemistry, (15th ICQC), June 8-13, 2015, which will take place in the beautiful campus of Tsinghua University in the city of Beijing, China. This conference series was initiated by the International Academy of Quantum Molecular Science (IAQMS, http://www.iaqms.org) in 1973 and held every third year since. It will be for the first time in China. The 15th ICQC succeeds the four recent meetings in Bonn (2003), Kyoto (2006), Helsinki (2009), and Boulder (2012). It has been probably the most important event for theoretical and computational chemists all over the world. Welcome you to Beijing for ICQC-2015! Please also notice the satellite meetings in Nanjing, Hefei, Xiamen, Dalian, Changchun, Beijing, and Kobe (Japan).