Self leveling floor material with flue gas desulfurization(FGD) gypsum was studied. A new kind of gypsum based self leveling mortar with fine fluidity, high strength, was developed with semi hydrated gypsum by mixing quartz sand, water reducing agent, retarder, water retaining agent, antifoaming agent and ethylene vinyl acetate(EVA) copolyment. The tests show that the main performance of this mortar reaches or exceeds the requirements specified in the standard of JC/T 1023—2007, such as fluidity, compressive strength，flexural strength and tensile strength.