International Workshop on Space Propulsion,IWSP 2018 will be held on September 9-15 in Harbin, China. The workshop is organized by Technical University of Munich, Harbin Institute of Technology, jointly organized by Northwestern Polytechnical University, Jiuzhou-Yunjian Space Technology Company and Shanghai Institute of Space Propulsion. Every year a specific topic of space propulsion will be chosen to be deeply discussed. The main topics this year concentrate on the fundamental thermodynamic problems of Liquid Space Propulsion.