An inflatable non-imaging solar concentrator water desalination system comprises an inflatable non-imaging stationary solar concentrator and shallow black basin type evaporator. The evaporator is made into a semi-close structure house like a stadium to surround the concentrator. An absorber made of black coating or porous absorption materials is placed on the basin of the concentrator. The evaporator consists of an inner holder, a outer holder, a freshwater collector, and a condenser to form a space for water to evaporate, and to be condensed and collected. The inflatable non-imaging solar concentrator is assembled with the evaporator in such a way that the output aperture of the solar concentrator is directly over the surface of the absorber